7f05d52c4c
is used on the right table of a LEFT JOIN. Ticket [e12a0ae526bb51c7]. FossilOrigin-Name: 704bb9a39acbee420c1d6ac9eb1466a02dd77d3334b938bfddf235973129b5fe
2472 lines
95 KiB
C
2472 lines
95 KiB
C
/*
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** 2015-06-06
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This module contains C code that generates VDBE code used to process
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** the WHERE clause of SQL statements.
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**
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** This file was split off from where.c on 2015-06-06 in order to reduce the
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** size of where.c and make it easier to edit. This file contains the routines
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** that actually generate the bulk of the WHERE loop code. The original where.c
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** file retains the code that does query planning and analysis.
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*/
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#include "sqliteInt.h"
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#include "whereInt.h"
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#ifndef SQLITE_OMIT_EXPLAIN
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/*
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** Return the name of the i-th column of the pIdx index.
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*/
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static const char *explainIndexColumnName(Index *pIdx, int i){
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i = pIdx->aiColumn[i];
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if( i==XN_EXPR ) return "<expr>";
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if( i==XN_ROWID ) return "rowid";
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return pIdx->pTable->aCol[i].zName;
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}
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/*
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** This routine is a helper for explainIndexRange() below
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**
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** pStr holds the text of an expression that we are building up one term
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** at a time. This routine adds a new term to the end of the expression.
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** Terms are separated by AND so add the "AND" text for second and subsequent
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** terms only.
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*/
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static void explainAppendTerm(
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StrAccum *pStr, /* The text expression being built */
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Index *pIdx, /* Index to read column names from */
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int nTerm, /* Number of terms */
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int iTerm, /* Zero-based index of first term. */
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int bAnd, /* Non-zero to append " AND " */
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const char *zOp /* Name of the operator */
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){
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int i;
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assert( nTerm>=1 );
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if( bAnd ) sqlite3_str_append(pStr, " AND ", 5);
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if( nTerm>1 ) sqlite3_str_append(pStr, "(", 1);
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for(i=0; i<nTerm; i++){
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if( i ) sqlite3_str_append(pStr, ",", 1);
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sqlite3_str_appendall(pStr, explainIndexColumnName(pIdx, iTerm+i));
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}
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if( nTerm>1 ) sqlite3_str_append(pStr, ")", 1);
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sqlite3_str_append(pStr, zOp, 1);
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if( nTerm>1 ) sqlite3_str_append(pStr, "(", 1);
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for(i=0; i<nTerm; i++){
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if( i ) sqlite3_str_append(pStr, ",", 1);
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sqlite3_str_append(pStr, "?", 1);
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}
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if( nTerm>1 ) sqlite3_str_append(pStr, ")", 1);
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}
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/*
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** Argument pLevel describes a strategy for scanning table pTab. This
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** function appends text to pStr that describes the subset of table
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** rows scanned by the strategy in the form of an SQL expression.
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**
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** For example, if the query:
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**
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** SELECT * FROM t1 WHERE a=1 AND b>2;
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**
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** is run and there is an index on (a, b), then this function returns a
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** string similar to:
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**
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** "a=? AND b>?"
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*/
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static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop){
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Index *pIndex = pLoop->u.btree.pIndex;
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u16 nEq = pLoop->u.btree.nEq;
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u16 nSkip = pLoop->nSkip;
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int i, j;
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if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
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sqlite3_str_append(pStr, " (", 2);
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for(i=0; i<nEq; i++){
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const char *z = explainIndexColumnName(pIndex, i);
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if( i ) sqlite3_str_append(pStr, " AND ", 5);
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sqlite3_str_appendf(pStr, i>=nSkip ? "%s=?" : "ANY(%s)", z);
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}
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j = i;
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if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
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explainAppendTerm(pStr, pIndex, pLoop->u.btree.nBtm, j, i, ">");
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i = 1;
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}
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if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
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explainAppendTerm(pStr, pIndex, pLoop->u.btree.nTop, j, i, "<");
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}
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sqlite3_str_append(pStr, ")", 1);
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}
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/*
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** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
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** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
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** defined at compile-time. If it is not a no-op, a single OP_Explain opcode
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** is added to the output to describe the table scan strategy in pLevel.
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**
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** If an OP_Explain opcode is added to the VM, its address is returned.
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** Otherwise, if no OP_Explain is coded, zero is returned.
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*/
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int sqlite3WhereExplainOneScan(
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Parse *pParse, /* Parse context */
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SrcList *pTabList, /* Table list this loop refers to */
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WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
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u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
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){
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int ret = 0;
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#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
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if( sqlite3ParseToplevel(pParse)->explain==2 )
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#endif
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{
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struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
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Vdbe *v = pParse->pVdbe; /* VM being constructed */
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sqlite3 *db = pParse->db; /* Database handle */
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int isSearch; /* True for a SEARCH. False for SCAN. */
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WhereLoop *pLoop; /* The controlling WhereLoop object */
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u32 flags; /* Flags that describe this loop */
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char *zMsg; /* Text to add to EQP output */
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StrAccum str; /* EQP output string */
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char zBuf[100]; /* Initial space for EQP output string */
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pLoop = pLevel->pWLoop;
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flags = pLoop->wsFlags;
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if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_OR_SUBCLAUSE) ) return 0;
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isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
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|| ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
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|| (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
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sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
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sqlite3_str_appendall(&str, isSearch ? "SEARCH" : "SCAN");
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if( pItem->pSelect ){
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sqlite3_str_appendf(&str, " SUBQUERY %u", pItem->pSelect->selId);
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}else{
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sqlite3_str_appendf(&str, " TABLE %s", pItem->zName);
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}
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if( pItem->zAlias ){
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sqlite3_str_appendf(&str, " AS %s", pItem->zAlias);
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}
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if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
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const char *zFmt = 0;
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Index *pIdx;
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assert( pLoop->u.btree.pIndex!=0 );
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pIdx = pLoop->u.btree.pIndex;
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assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
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if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
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if( isSearch ){
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zFmt = "PRIMARY KEY";
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}
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}else if( flags & WHERE_PARTIALIDX ){
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zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
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}else if( flags & WHERE_AUTO_INDEX ){
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zFmt = "AUTOMATIC COVERING INDEX";
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}else if( flags & WHERE_IDX_ONLY ){
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zFmt = "COVERING INDEX %s";
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}else{
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zFmt = "INDEX %s";
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}
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if( zFmt ){
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sqlite3_str_append(&str, " USING ", 7);
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sqlite3_str_appendf(&str, zFmt, pIdx->zName);
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explainIndexRange(&str, pLoop);
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}
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}else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
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const char *zRangeOp;
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if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
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zRangeOp = "=";
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}else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
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zRangeOp = ">? AND rowid<";
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}else if( flags&WHERE_BTM_LIMIT ){
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zRangeOp = ">";
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}else{
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assert( flags&WHERE_TOP_LIMIT);
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zRangeOp = "<";
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}
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sqlite3_str_appendf(&str,
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" USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);
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}
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#ifndef SQLITE_OMIT_VIRTUALTABLE
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else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
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sqlite3_str_appendf(&str, " VIRTUAL TABLE INDEX %d:%s",
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pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
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}
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#endif
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#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
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if( pLoop->nOut>=10 ){
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sqlite3_str_appendf(&str, " (~%llu rows)",
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sqlite3LogEstToInt(pLoop->nOut));
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}else{
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sqlite3_str_append(&str, " (~1 row)", 9);
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}
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#endif
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zMsg = sqlite3StrAccumFinish(&str);
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sqlite3ExplainBreakpoint("",zMsg);
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ret = sqlite3VdbeAddOp4(v, OP_Explain, sqlite3VdbeCurrentAddr(v),
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pParse->addrExplain, 0, zMsg,P4_DYNAMIC);
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}
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return ret;
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}
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#endif /* SQLITE_OMIT_EXPLAIN */
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#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
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/*
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** Configure the VM passed as the first argument with an
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** sqlite3_stmt_scanstatus() entry corresponding to the scan used to
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** implement level pLvl. Argument pSrclist is a pointer to the FROM
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** clause that the scan reads data from.
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**
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** If argument addrExplain is not 0, it must be the address of an
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** OP_Explain instruction that describes the same loop.
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*/
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void sqlite3WhereAddScanStatus(
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Vdbe *v, /* Vdbe to add scanstatus entry to */
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SrcList *pSrclist, /* FROM clause pLvl reads data from */
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WhereLevel *pLvl, /* Level to add scanstatus() entry for */
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int addrExplain /* Address of OP_Explain (or 0) */
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){
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const char *zObj = 0;
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WhereLoop *pLoop = pLvl->pWLoop;
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if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 && pLoop->u.btree.pIndex!=0 ){
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zObj = pLoop->u.btree.pIndex->zName;
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}else{
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zObj = pSrclist->a[pLvl->iFrom].zName;
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}
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sqlite3VdbeScanStatus(
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v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
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);
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}
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#endif
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/*
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** Disable a term in the WHERE clause. Except, do not disable the term
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** if it controls a LEFT OUTER JOIN and it did not originate in the ON
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** or USING clause of that join.
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**
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** Consider the term t2.z='ok' in the following queries:
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**
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** (1) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
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** (2) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
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** (3) SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
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**
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** The t2.z='ok' is disabled in the in (2) because it originates
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** in the ON clause. The term is disabled in (3) because it is not part
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** of a LEFT OUTER JOIN. In (1), the term is not disabled.
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**
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** Disabling a term causes that term to not be tested in the inner loop
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** of the join. Disabling is an optimization. When terms are satisfied
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** by indices, we disable them to prevent redundant tests in the inner
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** loop. We would get the correct results if nothing were ever disabled,
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** but joins might run a little slower. The trick is to disable as much
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** as we can without disabling too much. If we disabled in (1), we'd get
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** the wrong answer. See ticket #813.
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**
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** If all the children of a term are disabled, then that term is also
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** automatically disabled. In this way, terms get disabled if derived
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** virtual terms are tested first. For example:
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**
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** x GLOB 'abc*' AND x>='abc' AND x<'acd'
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** \___________/ \______/ \_____/
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** parent child1 child2
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**
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** Only the parent term was in the original WHERE clause. The child1
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** and child2 terms were added by the LIKE optimization. If both of
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** the virtual child terms are valid, then testing of the parent can be
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** skipped.
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**
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** Usually the parent term is marked as TERM_CODED. But if the parent
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** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
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** The TERM_LIKECOND marking indicates that the term should be coded inside
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** a conditional such that is only evaluated on the second pass of a
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** LIKE-optimization loop, when scanning BLOBs instead of strings.
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*/
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static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
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int nLoop = 0;
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assert( pTerm!=0 );
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while( (pTerm->wtFlags & TERM_CODED)==0
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&& (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
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&& (pLevel->notReady & pTerm->prereqAll)==0
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){
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if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
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pTerm->wtFlags |= TERM_LIKECOND;
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}else{
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pTerm->wtFlags |= TERM_CODED;
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}
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if( pTerm->iParent<0 ) break;
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pTerm = &pTerm->pWC->a[pTerm->iParent];
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assert( pTerm!=0 );
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pTerm->nChild--;
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if( pTerm->nChild!=0 ) break;
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nLoop++;
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}
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}
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/*
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** Code an OP_Affinity opcode to apply the column affinity string zAff
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** to the n registers starting at base.
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**
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** As an optimization, SQLITE_AFF_BLOB and SQLITE_AFF_NONE entries (which
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** are no-ops) at the beginning and end of zAff are ignored. If all entries
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** in zAff are SQLITE_AFF_BLOB or SQLITE_AFF_NONE, then no code gets generated.
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**
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** This routine makes its own copy of zAff so that the caller is free
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** to modify zAff after this routine returns.
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*/
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static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
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Vdbe *v = pParse->pVdbe;
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if( zAff==0 ){
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assert( pParse->db->mallocFailed );
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return;
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}
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assert( v!=0 );
|
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/* Adjust base and n to skip over SQLITE_AFF_BLOB and SQLITE_AFF_NONE
|
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** entries at the beginning and end of the affinity string.
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*/
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assert( SQLITE_AFF_NONE<SQLITE_AFF_BLOB );
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while( n>0 && zAff[0]<=SQLITE_AFF_BLOB ){
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n--;
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base++;
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zAff++;
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}
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while( n>1 && zAff[n-1]<=SQLITE_AFF_BLOB ){
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n--;
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}
|
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/* Code the OP_Affinity opcode if there is anything left to do. */
|
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if( n>0 ){
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sqlite3VdbeAddOp4(v, OP_Affinity, base, n, 0, zAff, n);
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}
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}
|
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|
|
/*
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|
** Expression pRight, which is the RHS of a comparison operation, is
|
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** either a vector of n elements or, if n==1, a scalar expression.
|
|
** Before the comparison operation, affinity zAff is to be applied
|
|
** to the pRight values. This function modifies characters within the
|
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** affinity string to SQLITE_AFF_BLOB if either:
|
|
**
|
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** * the comparison will be performed with no affinity, or
|
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** * the affinity change in zAff is guaranteed not to change the value.
|
|
*/
|
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static void updateRangeAffinityStr(
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Expr *pRight, /* RHS of comparison */
|
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int n, /* Number of vector elements in comparison */
|
|
char *zAff /* Affinity string to modify */
|
|
){
|
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int i;
|
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for(i=0; i<n; i++){
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Expr *p = sqlite3VectorFieldSubexpr(pRight, i);
|
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if( sqlite3CompareAffinity(p, zAff[i])==SQLITE_AFF_BLOB
|
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|| sqlite3ExprNeedsNoAffinityChange(p, zAff[i])
|
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){
|
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zAff[i] = SQLITE_AFF_BLOB;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
** pX is an expression of the form: (vector) IN (SELECT ...)
|
|
** In other words, it is a vector IN operator with a SELECT clause on the
|
|
** LHS. But not all terms in the vector are indexable and the terms might
|
|
** not be in the correct order for indexing.
|
|
**
|
|
** This routine makes a copy of the input pX expression and then adjusts
|
|
** the vector on the LHS with corresponding changes to the SELECT so that
|
|
** the vector contains only index terms and those terms are in the correct
|
|
** order. The modified IN expression is returned. The caller is responsible
|
|
** for deleting the returned expression.
|
|
**
|
|
** Example:
|
|
**
|
|
** CREATE TABLE t1(a,b,c,d,e,f);
|
|
** CREATE INDEX t1x1 ON t1(e,c);
|
|
** SELECT * FROM t1 WHERE (a,b,c,d,e) IN (SELECT v,w,x,y,z FROM t2)
|
|
** \_______________________________________/
|
|
** The pX expression
|
|
**
|
|
** Since only columns e and c can be used with the index, in that order,
|
|
** the modified IN expression that is returned will be:
|
|
**
|
|
** (e,c) IN (SELECT z,x FROM t2)
|
|
**
|
|
** The reduced pX is different from the original (obviously) and thus is
|
|
** only used for indexing, to improve performance. The original unaltered
|
|
** IN expression must also be run on each output row for correctness.
|
|
*/
|
|
static Expr *removeUnindexableInClauseTerms(
|
|
Parse *pParse, /* The parsing context */
|
|
int iEq, /* Look at loop terms starting here */
|
|
WhereLoop *pLoop, /* The current loop */
|
|
Expr *pX /* The IN expression to be reduced */
|
|
){
|
|
sqlite3 *db = pParse->db;
|
|
Expr *pNew;
|
|
pNew = sqlite3ExprDup(db, pX, 0);
|
|
if( db->mallocFailed==0 ){
|
|
ExprList *pOrigRhs = pNew->x.pSelect->pEList; /* Original unmodified RHS */
|
|
ExprList *pOrigLhs = pNew->pLeft->x.pList; /* Original unmodified LHS */
|
|
ExprList *pRhs = 0; /* New RHS after modifications */
|
|
ExprList *pLhs = 0; /* New LHS after mods */
|
|
int i; /* Loop counter */
|
|
Select *pSelect; /* Pointer to the SELECT on the RHS */
|
|
|
|
for(i=iEq; i<pLoop->nLTerm; i++){
|
|
if( pLoop->aLTerm[i]->pExpr==pX ){
|
|
int iField = pLoop->aLTerm[i]->iField - 1;
|
|
if( pOrigRhs->a[iField].pExpr==0 ) continue; /* Duplicate PK column */
|
|
pRhs = sqlite3ExprListAppend(pParse, pRhs, pOrigRhs->a[iField].pExpr);
|
|
pOrigRhs->a[iField].pExpr = 0;
|
|
assert( pOrigLhs->a[iField].pExpr!=0 );
|
|
pLhs = sqlite3ExprListAppend(pParse, pLhs, pOrigLhs->a[iField].pExpr);
|
|
pOrigLhs->a[iField].pExpr = 0;
|
|
}
|
|
}
|
|
sqlite3ExprListDelete(db, pOrigRhs);
|
|
sqlite3ExprListDelete(db, pOrigLhs);
|
|
pNew->pLeft->x.pList = pLhs;
|
|
pNew->x.pSelect->pEList = pRhs;
|
|
if( pLhs && pLhs->nExpr==1 ){
|
|
/* Take care here not to generate a TK_VECTOR containing only a
|
|
** single value. Since the parser never creates such a vector, some
|
|
** of the subroutines do not handle this case. */
|
|
Expr *p = pLhs->a[0].pExpr;
|
|
pLhs->a[0].pExpr = 0;
|
|
sqlite3ExprDelete(db, pNew->pLeft);
|
|
pNew->pLeft = p;
|
|
}
|
|
pSelect = pNew->x.pSelect;
|
|
if( pSelect->pOrderBy ){
|
|
/* If the SELECT statement has an ORDER BY clause, zero the
|
|
** iOrderByCol variables. These are set to non-zero when an
|
|
** ORDER BY term exactly matches one of the terms of the
|
|
** result-set. Since the result-set of the SELECT statement may
|
|
** have been modified or reordered, these variables are no longer
|
|
** set correctly. Since setting them is just an optimization,
|
|
** it's easiest just to zero them here. */
|
|
ExprList *pOrderBy = pSelect->pOrderBy;
|
|
for(i=0; i<pOrderBy->nExpr; i++){
|
|
pOrderBy->a[i].u.x.iOrderByCol = 0;
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
printf("For indexing, change the IN expr:\n");
|
|
sqlite3TreeViewExpr(0, pX, 0);
|
|
printf("Into:\n");
|
|
sqlite3TreeViewExpr(0, pNew, 0);
|
|
#endif
|
|
}
|
|
return pNew;
|
|
}
|
|
|
|
|
|
/*
|
|
** Generate code for a single equality term of the WHERE clause. An equality
|
|
** term can be either X=expr or X IN (...). pTerm is the term to be
|
|
** coded.
|
|
**
|
|
** The current value for the constraint is left in a register, the index
|
|
** of which is returned. An attempt is made store the result in iTarget but
|
|
** this is only guaranteed for TK_ISNULL and TK_IN constraints. If the
|
|
** constraint is a TK_EQ or TK_IS, then the current value might be left in
|
|
** some other register and it is the caller's responsibility to compensate.
|
|
**
|
|
** For a constraint of the form X=expr, the expression is evaluated in
|
|
** straight-line code. For constraints of the form X IN (...)
|
|
** this routine sets up a loop that will iterate over all values of X.
|
|
*/
|
|
static int codeEqualityTerm(
|
|
Parse *pParse, /* The parsing context */
|
|
WhereTerm *pTerm, /* The term of the WHERE clause to be coded */
|
|
WhereLevel *pLevel, /* The level of the FROM clause we are working on */
|
|
int iEq, /* Index of the equality term within this level */
|
|
int bRev, /* True for reverse-order IN operations */
|
|
int iTarget /* Attempt to leave results in this register */
|
|
){
|
|
Expr *pX = pTerm->pExpr;
|
|
Vdbe *v = pParse->pVdbe;
|
|
int iReg; /* Register holding results */
|
|
|
|
assert( pLevel->pWLoop->aLTerm[iEq]==pTerm );
|
|
assert( iTarget>0 );
|
|
if( pX->op==TK_EQ || pX->op==TK_IS ){
|
|
iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
|
|
}else if( pX->op==TK_ISNULL ){
|
|
iReg = iTarget;
|
|
sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
|
|
#ifndef SQLITE_OMIT_SUBQUERY
|
|
}else{
|
|
int eType = IN_INDEX_NOOP;
|
|
int iTab;
|
|
struct InLoop *pIn;
|
|
WhereLoop *pLoop = pLevel->pWLoop;
|
|
int i;
|
|
int nEq = 0;
|
|
int *aiMap = 0;
|
|
|
|
if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
|
|
&& pLoop->u.btree.pIndex!=0
|
|
&& pLoop->u.btree.pIndex->aSortOrder[iEq]
|
|
){
|
|
testcase( iEq==0 );
|
|
testcase( bRev );
|
|
bRev = !bRev;
|
|
}
|
|
assert( pX->op==TK_IN );
|
|
iReg = iTarget;
|
|
|
|
for(i=0; i<iEq; i++){
|
|
if( pLoop->aLTerm[i] && pLoop->aLTerm[i]->pExpr==pX ){
|
|
disableTerm(pLevel, pTerm);
|
|
return iTarget;
|
|
}
|
|
}
|
|
for(i=iEq;i<pLoop->nLTerm; i++){
|
|
assert( pLoop->aLTerm[i]!=0 );
|
|
if( pLoop->aLTerm[i]->pExpr==pX ) nEq++;
|
|
}
|
|
|
|
iTab = 0;
|
|
if( (pX->flags & EP_xIsSelect)==0 || pX->x.pSelect->pEList->nExpr==1 ){
|
|
eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0, &iTab);
|
|
}else{
|
|
sqlite3 *db = pParse->db;
|
|
pX = removeUnindexableInClauseTerms(pParse, iEq, pLoop, pX);
|
|
|
|
if( !db->mallocFailed ){
|
|
aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*nEq);
|
|
eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap, &iTab);
|
|
pTerm->pExpr->iTable = iTab;
|
|
}
|
|
sqlite3ExprDelete(db, pX);
|
|
pX = pTerm->pExpr;
|
|
}
|
|
|
|
if( eType==IN_INDEX_INDEX_DESC ){
|
|
testcase( bRev );
|
|
bRev = !bRev;
|
|
}
|
|
sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
|
|
VdbeCoverageIf(v, bRev);
|
|
VdbeCoverageIf(v, !bRev);
|
|
assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
|
|
|
|
pLoop->wsFlags |= WHERE_IN_ABLE;
|
|
if( pLevel->u.in.nIn==0 ){
|
|
pLevel->addrNxt = sqlite3VdbeMakeLabel(pParse);
|
|
}
|
|
|
|
i = pLevel->u.in.nIn;
|
|
pLevel->u.in.nIn += nEq;
|
|
pLevel->u.in.aInLoop =
|
|
sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
|
|
sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
|
|
pIn = pLevel->u.in.aInLoop;
|
|
if( pIn ){
|
|
int iMap = 0; /* Index in aiMap[] */
|
|
pIn += i;
|
|
for(i=iEq;i<pLoop->nLTerm; i++){
|
|
if( pLoop->aLTerm[i]->pExpr==pX ){
|
|
int iOut = iReg + i - iEq;
|
|
if( eType==IN_INDEX_ROWID ){
|
|
pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iOut);
|
|
}else{
|
|
int iCol = aiMap ? aiMap[iMap++] : 0;
|
|
pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);
|
|
}
|
|
sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v);
|
|
if( i==iEq ){
|
|
pIn->iCur = iTab;
|
|
pIn->eEndLoopOp = bRev ? OP_Prev : OP_Next;
|
|
if( iEq>0 ){
|
|
pIn->iBase = iReg - i;
|
|
pIn->nPrefix = i;
|
|
pLoop->wsFlags |= WHERE_IN_EARLYOUT;
|
|
}else{
|
|
pIn->nPrefix = 0;
|
|
}
|
|
}else{
|
|
pIn->eEndLoopOp = OP_Noop;
|
|
}
|
|
pIn++;
|
|
}
|
|
}
|
|
}else{
|
|
pLevel->u.in.nIn = 0;
|
|
}
|
|
sqlite3DbFree(pParse->db, aiMap);
|
|
#endif
|
|
}
|
|
disableTerm(pLevel, pTerm);
|
|
return iReg;
|
|
}
|
|
|
|
/*
|
|
** Generate code that will evaluate all == and IN constraints for an
|
|
** index scan.
|
|
**
|
|
** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
|
|
** Suppose the WHERE clause is this: a==5 AND b IN (1,2,3) AND c>5 AND c<10
|
|
** The index has as many as three equality constraints, but in this
|
|
** example, the third "c" value is an inequality. So only two
|
|
** constraints are coded. This routine will generate code to evaluate
|
|
** a==5 and b IN (1,2,3). The current values for a and b will be stored
|
|
** in consecutive registers and the index of the first register is returned.
|
|
**
|
|
** In the example above nEq==2. But this subroutine works for any value
|
|
** of nEq including 0. If nEq==0, this routine is nearly a no-op.
|
|
** The only thing it does is allocate the pLevel->iMem memory cell and
|
|
** compute the affinity string.
|
|
**
|
|
** The nExtraReg parameter is 0 or 1. It is 0 if all WHERE clause constraints
|
|
** are == or IN and are covered by the nEq. nExtraReg is 1 if there is
|
|
** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
|
|
** occurs after the nEq quality constraints.
|
|
**
|
|
** This routine allocates a range of nEq+nExtraReg memory cells and returns
|
|
** the index of the first memory cell in that range. The code that
|
|
** calls this routine will use that memory range to store keys for
|
|
** start and termination conditions of the loop.
|
|
** key value of the loop. If one or more IN operators appear, then
|
|
** this routine allocates an additional nEq memory cells for internal
|
|
** use.
|
|
**
|
|
** Before returning, *pzAff is set to point to a buffer containing a
|
|
** copy of the column affinity string of the index allocated using
|
|
** sqlite3DbMalloc(). Except, entries in the copy of the string associated
|
|
** with equality constraints that use BLOB or NONE affinity are set to
|
|
** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
|
|
**
|
|
** CREATE TABLE t1(a TEXT PRIMARY KEY, b);
|
|
** SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
|
|
**
|
|
** In the example above, the index on t1(a) has TEXT affinity. But since
|
|
** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
|
|
** no conversion should be attempted before using a t2.b value as part of
|
|
** a key to search the index. Hence the first byte in the returned affinity
|
|
** string in this example would be set to SQLITE_AFF_BLOB.
|
|
*/
|
|
static int codeAllEqualityTerms(
|
|
Parse *pParse, /* Parsing context */
|
|
WhereLevel *pLevel, /* Which nested loop of the FROM we are coding */
|
|
int bRev, /* Reverse the order of IN operators */
|
|
int nExtraReg, /* Number of extra registers to allocate */
|
|
char **pzAff /* OUT: Set to point to affinity string */
|
|
){
|
|
u16 nEq; /* The number of == or IN constraints to code */
|
|
u16 nSkip; /* Number of left-most columns to skip */
|
|
Vdbe *v = pParse->pVdbe; /* The vm under construction */
|
|
Index *pIdx; /* The index being used for this loop */
|
|
WhereTerm *pTerm; /* A single constraint term */
|
|
WhereLoop *pLoop; /* The WhereLoop object */
|
|
int j; /* Loop counter */
|
|
int regBase; /* Base register */
|
|
int nReg; /* Number of registers to allocate */
|
|
char *zAff; /* Affinity string to return */
|
|
|
|
/* This module is only called on query plans that use an index. */
|
|
pLoop = pLevel->pWLoop;
|
|
assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
|
|
nEq = pLoop->u.btree.nEq;
|
|
nSkip = pLoop->nSkip;
|
|
pIdx = pLoop->u.btree.pIndex;
|
|
assert( pIdx!=0 );
|
|
|
|
/* Figure out how many memory cells we will need then allocate them.
|
|
*/
|
|
regBase = pParse->nMem + 1;
|
|
nReg = pLoop->u.btree.nEq + nExtraReg;
|
|
pParse->nMem += nReg;
|
|
|
|
zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));
|
|
assert( zAff!=0 || pParse->db->mallocFailed );
|
|
|
|
if( nSkip ){
|
|
int iIdxCur = pLevel->iIdxCur;
|
|
sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
|
|
VdbeCoverageIf(v, bRev==0);
|
|
VdbeCoverageIf(v, bRev!=0);
|
|
VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
|
|
j = sqlite3VdbeAddOp0(v, OP_Goto);
|
|
pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
|
|
iIdxCur, 0, regBase, nSkip);
|
|
VdbeCoverageIf(v, bRev==0);
|
|
VdbeCoverageIf(v, bRev!=0);
|
|
sqlite3VdbeJumpHere(v, j);
|
|
for(j=0; j<nSkip; j++){
|
|
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
|
|
testcase( pIdx->aiColumn[j]==XN_EXPR );
|
|
VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
|
|
}
|
|
}
|
|
|
|
/* Evaluate the equality constraints
|
|
*/
|
|
assert( zAff==0 || (int)strlen(zAff)>=nEq );
|
|
for(j=nSkip; j<nEq; j++){
|
|
int r1;
|
|
pTerm = pLoop->aLTerm[j];
|
|
assert( pTerm!=0 );
|
|
/* The following testcase is true for indices with redundant columns.
|
|
** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
|
|
testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
|
|
testcase( pTerm->wtFlags & TERM_VIRTUAL );
|
|
r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
|
|
if( r1!=regBase+j ){
|
|
if( nReg==1 ){
|
|
sqlite3ReleaseTempReg(pParse, regBase);
|
|
regBase = r1;
|
|
}else{
|
|
sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
|
|
}
|
|
}
|
|
if( pTerm->eOperator & WO_IN ){
|
|
if( pTerm->pExpr->flags & EP_xIsSelect ){
|
|
/* No affinity ever needs to be (or should be) applied to a value
|
|
** from the RHS of an "? IN (SELECT ...)" expression. The
|
|
** sqlite3FindInIndex() routine has already ensured that the
|
|
** affinity of the comparison has been applied to the value. */
|
|
if( zAff ) zAff[j] = SQLITE_AFF_BLOB;
|
|
}
|
|
}else if( (pTerm->eOperator & WO_ISNULL)==0 ){
|
|
Expr *pRight = pTerm->pExpr->pRight;
|
|
if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
|
|
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
|
|
VdbeCoverage(v);
|
|
}
|
|
if( zAff ){
|
|
if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
|
|
zAff[j] = SQLITE_AFF_BLOB;
|
|
}
|
|
if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
|
|
zAff[j] = SQLITE_AFF_BLOB;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
*pzAff = zAff;
|
|
return regBase;
|
|
}
|
|
|
|
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
|
|
/*
|
|
** If the most recently coded instruction is a constant range constraint
|
|
** (a string literal) that originated from the LIKE optimization, then
|
|
** set P3 and P5 on the OP_String opcode so that the string will be cast
|
|
** to a BLOB at appropriate times.
|
|
**
|
|
** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
|
|
** expression: "x>='ABC' AND x<'abd'". But this requires that the range
|
|
** scan loop run twice, once for strings and a second time for BLOBs.
|
|
** The OP_String opcodes on the second pass convert the upper and lower
|
|
** bound string constants to blobs. This routine makes the necessary changes
|
|
** to the OP_String opcodes for that to happen.
|
|
**
|
|
** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then
|
|
** only the one pass through the string space is required, so this routine
|
|
** becomes a no-op.
|
|
*/
|
|
static void whereLikeOptimizationStringFixup(
|
|
Vdbe *v, /* prepared statement under construction */
|
|
WhereLevel *pLevel, /* The loop that contains the LIKE operator */
|
|
WhereTerm *pTerm /* The upper or lower bound just coded */
|
|
){
|
|
if( pTerm->wtFlags & TERM_LIKEOPT ){
|
|
VdbeOp *pOp;
|
|
assert( pLevel->iLikeRepCntr>0 );
|
|
pOp = sqlite3VdbeGetOp(v, -1);
|
|
assert( pOp!=0 );
|
|
assert( pOp->opcode==OP_String8
|
|
|| pTerm->pWC->pWInfo->pParse->db->mallocFailed );
|
|
pOp->p3 = (int)(pLevel->iLikeRepCntr>>1); /* Register holding counter */
|
|
pOp->p5 = (u8)(pLevel->iLikeRepCntr&1); /* ASC or DESC */
|
|
}
|
|
}
|
|
#else
|
|
# define whereLikeOptimizationStringFixup(A,B,C)
|
|
#endif
|
|
|
|
#ifdef SQLITE_ENABLE_CURSOR_HINTS
|
|
/*
|
|
** Information is passed from codeCursorHint() down to individual nodes of
|
|
** the expression tree (by sqlite3WalkExpr()) using an instance of this
|
|
** structure.
|
|
*/
|
|
struct CCurHint {
|
|
int iTabCur; /* Cursor for the main table */
|
|
int iIdxCur; /* Cursor for the index, if pIdx!=0. Unused otherwise */
|
|
Index *pIdx; /* The index used to access the table */
|
|
};
|
|
|
|
/*
|
|
** This function is called for every node of an expression that is a candidate
|
|
** for a cursor hint on an index cursor. For TK_COLUMN nodes that reference
|
|
** the table CCurHint.iTabCur, verify that the same column can be
|
|
** accessed through the index. If it cannot, then set pWalker->eCode to 1.
|
|
*/
|
|
static int codeCursorHintCheckExpr(Walker *pWalker, Expr *pExpr){
|
|
struct CCurHint *pHint = pWalker->u.pCCurHint;
|
|
assert( pHint->pIdx!=0 );
|
|
if( pExpr->op==TK_COLUMN
|
|
&& pExpr->iTable==pHint->iTabCur
|
|
&& sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn)<0
|
|
){
|
|
pWalker->eCode = 1;
|
|
}
|
|
return WRC_Continue;
|
|
}
|
|
|
|
/*
|
|
** Test whether or not expression pExpr, which was part of a WHERE clause,
|
|
** should be included in the cursor-hint for a table that is on the rhs
|
|
** of a LEFT JOIN. Set Walker.eCode to non-zero before returning if the
|
|
** expression is not suitable.
|
|
**
|
|
** An expression is unsuitable if it might evaluate to non NULL even if
|
|
** a TK_COLUMN node that does affect the value of the expression is set
|
|
** to NULL. For example:
|
|
**
|
|
** col IS NULL
|
|
** col IS NOT NULL
|
|
** coalesce(col, 1)
|
|
** CASE WHEN col THEN 0 ELSE 1 END
|
|
*/
|
|
static int codeCursorHintIsOrFunction(Walker *pWalker, Expr *pExpr){
|
|
if( pExpr->op==TK_IS
|
|
|| pExpr->op==TK_ISNULL || pExpr->op==TK_ISNOT
|
|
|| pExpr->op==TK_NOTNULL || pExpr->op==TK_CASE
|
|
){
|
|
pWalker->eCode = 1;
|
|
}else if( pExpr->op==TK_FUNCTION ){
|
|
int d1;
|
|
char d2[4];
|
|
if( 0==sqlite3IsLikeFunction(pWalker->pParse->db, pExpr, &d1, d2) ){
|
|
pWalker->eCode = 1;
|
|
}
|
|
}
|
|
|
|
return WRC_Continue;
|
|
}
|
|
|
|
|
|
/*
|
|
** This function is called on every node of an expression tree used as an
|
|
** argument to the OP_CursorHint instruction. If the node is a TK_COLUMN
|
|
** that accesses any table other than the one identified by
|
|
** CCurHint.iTabCur, then do the following:
|
|
**
|
|
** 1) allocate a register and code an OP_Column instruction to read
|
|
** the specified column into the new register, and
|
|
**
|
|
** 2) transform the expression node to a TK_REGISTER node that reads
|
|
** from the newly populated register.
|
|
**
|
|
** Also, if the node is a TK_COLUMN that does access the table idenified
|
|
** by pCCurHint.iTabCur, and an index is being used (which we will
|
|
** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into
|
|
** an access of the index rather than the original table.
|
|
*/
|
|
static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
|
|
int rc = WRC_Continue;
|
|
struct CCurHint *pHint = pWalker->u.pCCurHint;
|
|
if( pExpr->op==TK_COLUMN ){
|
|
if( pExpr->iTable!=pHint->iTabCur ){
|
|
int reg = ++pWalker->pParse->nMem; /* Register for column value */
|
|
sqlite3ExprCode(pWalker->pParse, pExpr, reg);
|
|
pExpr->op = TK_REGISTER;
|
|
pExpr->iTable = reg;
|
|
}else if( pHint->pIdx!=0 ){
|
|
pExpr->iTable = pHint->iIdxCur;
|
|
pExpr->iColumn = sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn);
|
|
assert( pExpr->iColumn>=0 );
|
|
}
|
|
}else if( pExpr->op==TK_AGG_FUNCTION ){
|
|
/* An aggregate function in the WHERE clause of a query means this must
|
|
** be a correlated sub-query, and expression pExpr is an aggregate from
|
|
** the parent context. Do not walk the function arguments in this case.
|
|
**
|
|
** todo: It should be possible to replace this node with a TK_REGISTER
|
|
** expression, as the result of the expression must be stored in a
|
|
** register at this point. The same holds for TK_AGG_COLUMN nodes. */
|
|
rc = WRC_Prune;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Insert an OP_CursorHint instruction if it is appropriate to do so.
|
|
*/
|
|
static void codeCursorHint(
|
|
struct SrcList_item *pTabItem, /* FROM clause item */
|
|
WhereInfo *pWInfo, /* The where clause */
|
|
WhereLevel *pLevel, /* Which loop to provide hints for */
|
|
WhereTerm *pEndRange /* Hint this end-of-scan boundary term if not NULL */
|
|
){
|
|
Parse *pParse = pWInfo->pParse;
|
|
sqlite3 *db = pParse->db;
|
|
Vdbe *v = pParse->pVdbe;
|
|
Expr *pExpr = 0;
|
|
WhereLoop *pLoop = pLevel->pWLoop;
|
|
int iCur;
|
|
WhereClause *pWC;
|
|
WhereTerm *pTerm;
|
|
int i, j;
|
|
struct CCurHint sHint;
|
|
Walker sWalker;
|
|
|
|
if( OptimizationDisabled(db, SQLITE_CursorHints) ) return;
|
|
iCur = pLevel->iTabCur;
|
|
assert( iCur==pWInfo->pTabList->a[pLevel->iFrom].iCursor );
|
|
sHint.iTabCur = iCur;
|
|
sHint.iIdxCur = pLevel->iIdxCur;
|
|
sHint.pIdx = pLoop->u.btree.pIndex;
|
|
memset(&sWalker, 0, sizeof(sWalker));
|
|
sWalker.pParse = pParse;
|
|
sWalker.u.pCCurHint = &sHint;
|
|
pWC = &pWInfo->sWC;
|
|
for(i=0; i<pWC->nTerm; i++){
|
|
pTerm = &pWC->a[i];
|
|
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
|
|
if( pTerm->prereqAll & pLevel->notReady ) continue;
|
|
|
|
/* Any terms specified as part of the ON(...) clause for any LEFT
|
|
** JOIN for which the current table is not the rhs are omitted
|
|
** from the cursor-hint.
|
|
**
|
|
** If this table is the rhs of a LEFT JOIN, "IS" or "IS NULL" terms
|
|
** that were specified as part of the WHERE clause must be excluded.
|
|
** This is to address the following:
|
|
**
|
|
** SELECT ... t1 LEFT JOIN t2 ON (t1.a=t2.b) WHERE t2.c IS NULL;
|
|
**
|
|
** Say there is a single row in t2 that matches (t1.a=t2.b), but its
|
|
** t2.c values is not NULL. If the (t2.c IS NULL) constraint is
|
|
** pushed down to the cursor, this row is filtered out, causing
|
|
** SQLite to synthesize a row of NULL values. Which does match the
|
|
** WHERE clause, and so the query returns a row. Which is incorrect.
|
|
**
|
|
** For the same reason, WHERE terms such as:
|
|
**
|
|
** WHERE 1 = (t2.c IS NULL)
|
|
**
|
|
** are also excluded. See codeCursorHintIsOrFunction() for details.
|
|
*/
|
|
if( pTabItem->fg.jointype & JT_LEFT ){
|
|
Expr *pExpr = pTerm->pExpr;
|
|
if( !ExprHasProperty(pExpr, EP_FromJoin)
|
|
|| pExpr->iRightJoinTable!=pTabItem->iCursor
|
|
){
|
|
sWalker.eCode = 0;
|
|
sWalker.xExprCallback = codeCursorHintIsOrFunction;
|
|
sqlite3WalkExpr(&sWalker, pTerm->pExpr);
|
|
if( sWalker.eCode ) continue;
|
|
}
|
|
}else{
|
|
if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;
|
|
}
|
|
|
|
/* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize
|
|
** the cursor. These terms are not needed as hints for a pure range
|
|
** scan (that has no == terms) so omit them. */
|
|
if( pLoop->u.btree.nEq==0 && pTerm!=pEndRange ){
|
|
for(j=0; j<pLoop->nLTerm && pLoop->aLTerm[j]!=pTerm; j++){}
|
|
if( j<pLoop->nLTerm ) continue;
|
|
}
|
|
|
|
/* No subqueries or non-deterministic functions allowed */
|
|
if( sqlite3ExprContainsSubquery(pTerm->pExpr) ) continue;
|
|
|
|
/* For an index scan, make sure referenced columns are actually in
|
|
** the index. */
|
|
if( sHint.pIdx!=0 ){
|
|
sWalker.eCode = 0;
|
|
sWalker.xExprCallback = codeCursorHintCheckExpr;
|
|
sqlite3WalkExpr(&sWalker, pTerm->pExpr);
|
|
if( sWalker.eCode ) continue;
|
|
}
|
|
|
|
/* If we survive all prior tests, that means this term is worth hinting */
|
|
pExpr = sqlite3ExprAnd(pParse, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
|
|
}
|
|
if( pExpr!=0 ){
|
|
sWalker.xExprCallback = codeCursorHintFixExpr;
|
|
sqlite3WalkExpr(&sWalker, pExpr);
|
|
sqlite3VdbeAddOp4(v, OP_CursorHint,
|
|
(sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
|
|
(const char*)pExpr, P4_EXPR);
|
|
}
|
|
}
|
|
#else
|
|
# define codeCursorHint(A,B,C,D) /* No-op */
|
|
#endif /* SQLITE_ENABLE_CURSOR_HINTS */
|
|
|
|
/*
|
|
** Cursor iCur is open on an intkey b-tree (a table). Register iRowid contains
|
|
** a rowid value just read from cursor iIdxCur, open on index pIdx. This
|
|
** function generates code to do a deferred seek of cursor iCur to the
|
|
** rowid stored in register iRowid.
|
|
**
|
|
** Normally, this is just:
|
|
**
|
|
** OP_DeferredSeek $iCur $iRowid
|
|
**
|
|
** However, if the scan currently being coded is a branch of an OR-loop and
|
|
** the statement currently being coded is a SELECT, then P3 of OP_DeferredSeek
|
|
** is set to iIdxCur and P4 is set to point to an array of integers
|
|
** containing one entry for each column of the table cursor iCur is open
|
|
** on. For each table column, if the column is the i'th column of the
|
|
** index, then the corresponding array entry is set to (i+1). If the column
|
|
** does not appear in the index at all, the array entry is set to 0.
|
|
*/
|
|
static void codeDeferredSeek(
|
|
WhereInfo *pWInfo, /* Where clause context */
|
|
Index *pIdx, /* Index scan is using */
|
|
int iCur, /* Cursor for IPK b-tree */
|
|
int iIdxCur /* Index cursor */
|
|
){
|
|
Parse *pParse = pWInfo->pParse; /* Parse context */
|
|
Vdbe *v = pParse->pVdbe; /* Vdbe to generate code within */
|
|
|
|
assert( iIdxCur>0 );
|
|
assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
|
|
|
|
pWInfo->bDeferredSeek = 1;
|
|
sqlite3VdbeAddOp3(v, OP_DeferredSeek, iIdxCur, 0, iCur);
|
|
if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
|
|
&& DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)
|
|
){
|
|
int i;
|
|
Table *pTab = pIdx->pTable;
|
|
int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));
|
|
if( ai ){
|
|
ai[0] = pTab->nCol;
|
|
for(i=0; i<pIdx->nColumn-1; i++){
|
|
int x1, x2;
|
|
assert( pIdx->aiColumn[i]<pTab->nCol );
|
|
x1 = pIdx->aiColumn[i];
|
|
x2 = sqlite3TableColumnToStorage(pTab, x1);
|
|
testcase( x1!=x2 );
|
|
if( x1>=0 ) ai[x2+1] = i+1;
|
|
}
|
|
sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** If the expression passed as the second argument is a vector, generate
|
|
** code to write the first nReg elements of the vector into an array
|
|
** of registers starting with iReg.
|
|
**
|
|
** If the expression is not a vector, then nReg must be passed 1. In
|
|
** this case, generate code to evaluate the expression and leave the
|
|
** result in register iReg.
|
|
*/
|
|
static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){
|
|
assert( nReg>0 );
|
|
if( p && sqlite3ExprIsVector(p) ){
|
|
#ifndef SQLITE_OMIT_SUBQUERY
|
|
if( (p->flags & EP_xIsSelect) ){
|
|
Vdbe *v = pParse->pVdbe;
|
|
int iSelect;
|
|
assert( p->op==TK_SELECT );
|
|
iSelect = sqlite3CodeSubselect(pParse, p);
|
|
sqlite3VdbeAddOp3(v, OP_Copy, iSelect, iReg, nReg-1);
|
|
}else
|
|
#endif
|
|
{
|
|
int i;
|
|
ExprList *pList = p->x.pList;
|
|
assert( nReg<=pList->nExpr );
|
|
for(i=0; i<nReg; i++){
|
|
sqlite3ExprCode(pParse, pList->a[i].pExpr, iReg+i);
|
|
}
|
|
}
|
|
}else{
|
|
assert( nReg==1 );
|
|
sqlite3ExprCode(pParse, p, iReg);
|
|
}
|
|
}
|
|
|
|
/* An instance of the IdxExprTrans object carries information about a
|
|
** mapping from an expression on table columns into a column in an index
|
|
** down through the Walker.
|
|
*/
|
|
typedef struct IdxExprTrans {
|
|
Expr *pIdxExpr; /* The index expression */
|
|
int iTabCur; /* The cursor of the corresponding table */
|
|
int iIdxCur; /* The cursor for the index */
|
|
int iIdxCol; /* The column for the index */
|
|
int iTabCol; /* The column for the table */
|
|
WhereInfo *pWInfo; /* Complete WHERE clause information */
|
|
sqlite3 *db; /* Database connection (for malloc()) */
|
|
} IdxExprTrans;
|
|
|
|
/*
|
|
** Preserve pExpr on the WhereETrans list of the WhereInfo.
|
|
*/
|
|
static void preserveExpr(IdxExprTrans *pTrans, Expr *pExpr){
|
|
WhereExprMod *pNew;
|
|
pNew = sqlite3DbMallocRaw(pTrans->db, sizeof(*pNew));
|
|
if( pNew==0 ) return;
|
|
pNew->pNext = pTrans->pWInfo->pExprMods;
|
|
pTrans->pWInfo->pExprMods = pNew;
|
|
pNew->pExpr = pExpr;
|
|
memcpy(&pNew->orig, pExpr, sizeof(*pExpr));
|
|
}
|
|
|
|
/* The walker node callback used to transform matching expressions into
|
|
** a reference to an index column for an index on an expression.
|
|
**
|
|
** If pExpr matches, then transform it into a reference to the index column
|
|
** that contains the value of pExpr.
|
|
*/
|
|
static int whereIndexExprTransNode(Walker *p, Expr *pExpr){
|
|
IdxExprTrans *pX = p->u.pIdxTrans;
|
|
if( sqlite3ExprCompare(0, pExpr, pX->pIdxExpr, pX->iTabCur)==0 ){
|
|
preserveExpr(pX, pExpr);
|
|
pExpr->affExpr = sqlite3ExprAffinity(pExpr);
|
|
pExpr->op = TK_COLUMN;
|
|
pExpr->iTable = pX->iIdxCur;
|
|
pExpr->iColumn = pX->iIdxCol;
|
|
pExpr->y.pTab = 0;
|
|
testcase( ExprHasProperty(pExpr, EP_Skip) );
|
|
testcase( ExprHasProperty(pExpr, EP_Unlikely) );
|
|
ExprClearProperty(pExpr, EP_Skip|EP_Unlikely);
|
|
return WRC_Prune;
|
|
}else{
|
|
return WRC_Continue;
|
|
}
|
|
}
|
|
|
|
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
|
|
/* A walker node callback that translates a column reference to a table
|
|
** into a corresponding column reference of an index.
|
|
*/
|
|
static int whereIndexExprTransColumn(Walker *p, Expr *pExpr){
|
|
if( pExpr->op==TK_COLUMN ){
|
|
IdxExprTrans *pX = p->u.pIdxTrans;
|
|
if( pExpr->iTable==pX->iTabCur && pExpr->iColumn==pX->iTabCol ){
|
|
assert( pExpr->y.pTab!=0 );
|
|
preserveExpr(pX, pExpr);
|
|
pExpr->affExpr = sqlite3TableColumnAffinity(pExpr->y.pTab,pExpr->iColumn);
|
|
pExpr->iTable = pX->iIdxCur;
|
|
pExpr->iColumn = pX->iIdxCol;
|
|
pExpr->y.pTab = 0;
|
|
}
|
|
}
|
|
return WRC_Continue;
|
|
}
|
|
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
|
|
|
|
/*
|
|
** For an indexes on expression X, locate every instance of expression X
|
|
** in pExpr and change that subexpression into a reference to the appropriate
|
|
** column of the index.
|
|
**
|
|
** 2019-10-24: Updated to also translate references to a VIRTUAL column in
|
|
** the table into references to the corresponding (stored) column of the
|
|
** index.
|
|
*/
|
|
static void whereIndexExprTrans(
|
|
Index *pIdx, /* The Index */
|
|
int iTabCur, /* Cursor of the table that is being indexed */
|
|
int iIdxCur, /* Cursor of the index itself */
|
|
WhereInfo *pWInfo /* Transform expressions in this WHERE clause */
|
|
){
|
|
int iIdxCol; /* Column number of the index */
|
|
ExprList *aColExpr; /* Expressions that are indexed */
|
|
Table *pTab;
|
|
Walker w;
|
|
IdxExprTrans x;
|
|
aColExpr = pIdx->aColExpr;
|
|
if( aColExpr==0 && !pIdx->bHasVCol ){
|
|
/* The index does not reference any expressions or virtual columns
|
|
** so no translations are needed. */
|
|
return;
|
|
}
|
|
pTab = pIdx->pTable;
|
|
memset(&w, 0, sizeof(w));
|
|
w.u.pIdxTrans = &x;
|
|
x.iTabCur = iTabCur;
|
|
x.iIdxCur = iIdxCur;
|
|
x.pWInfo = pWInfo;
|
|
x.db = pWInfo->pParse->db;
|
|
for(iIdxCol=0; iIdxCol<pIdx->nColumn; iIdxCol++){
|
|
i16 iRef = pIdx->aiColumn[iIdxCol];
|
|
if( iRef==XN_EXPR ){
|
|
assert( aColExpr->a[iIdxCol].pExpr!=0 );
|
|
x.pIdxExpr = aColExpr->a[iIdxCol].pExpr;
|
|
if( sqlite3ExprIsConstant(x.pIdxExpr) ) continue;
|
|
w.xExprCallback = whereIndexExprTransNode;
|
|
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
|
|
}else if( iRef>=0
|
|
&& (pTab->aCol[iRef].colFlags & COLFLAG_VIRTUAL)!=0
|
|
&& (pTab->aCol[iRef].zColl==0
|
|
|| sqlite3StrICmp(pTab->aCol[iRef].zColl, sqlite3StrBINARY)==0)
|
|
){
|
|
/* Check to see if there are direct references to generated columns
|
|
** that are contained in the index. Pulling the generated column
|
|
** out of the index is an optimization only - the main table is always
|
|
** available if the index cannot be used. To avoid unnecessary
|
|
** complication, omit this optimization if the collating sequence for
|
|
** the column is non-standard */
|
|
x.iTabCol = iRef;
|
|
w.xExprCallback = whereIndexExprTransColumn;
|
|
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
|
|
}else{
|
|
continue;
|
|
}
|
|
x.iIdxCol = iIdxCol;
|
|
sqlite3WalkExpr(&w, pWInfo->pWhere);
|
|
sqlite3WalkExprList(&w, pWInfo->pOrderBy);
|
|
sqlite3WalkExprList(&w, pWInfo->pResultSet);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** The pTruth expression is always true because it is the WHERE clause
|
|
** a partial index that is driving a query loop. Look through all of the
|
|
** WHERE clause terms on the query, and if any of those terms must be
|
|
** true because pTruth is true, then mark those WHERE clause terms as
|
|
** coded.
|
|
*/
|
|
static void whereApplyPartialIndexConstraints(
|
|
Expr *pTruth,
|
|
int iTabCur,
|
|
WhereClause *pWC
|
|
){
|
|
int i;
|
|
WhereTerm *pTerm;
|
|
while( pTruth->op==TK_AND ){
|
|
whereApplyPartialIndexConstraints(pTruth->pLeft, iTabCur, pWC);
|
|
pTruth = pTruth->pRight;
|
|
}
|
|
for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
|
|
Expr *pExpr;
|
|
if( pTerm->wtFlags & TERM_CODED ) continue;
|
|
pExpr = pTerm->pExpr;
|
|
if( sqlite3ExprCompare(0, pExpr, pTruth, iTabCur)==0 ){
|
|
pTerm->wtFlags |= TERM_CODED;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Generate code for the start of the iLevel-th loop in the WHERE clause
|
|
** implementation described by pWInfo.
|
|
*/
|
|
Bitmask sqlite3WhereCodeOneLoopStart(
|
|
Parse *pParse, /* Parsing context */
|
|
Vdbe *v, /* Prepared statement under construction */
|
|
WhereInfo *pWInfo, /* Complete information about the WHERE clause */
|
|
int iLevel, /* Which level of pWInfo->a[] should be coded */
|
|
WhereLevel *pLevel, /* The current level pointer */
|
|
Bitmask notReady /* Which tables are currently available */
|
|
){
|
|
int j, k; /* Loop counters */
|
|
int iCur; /* The VDBE cursor for the table */
|
|
int addrNxt; /* Where to jump to continue with the next IN case */
|
|
int bRev; /* True if we need to scan in reverse order */
|
|
WhereLoop *pLoop; /* The WhereLoop object being coded */
|
|
WhereClause *pWC; /* Decomposition of the entire WHERE clause */
|
|
WhereTerm *pTerm; /* A WHERE clause term */
|
|
sqlite3 *db; /* Database connection */
|
|
struct SrcList_item *pTabItem; /* FROM clause term being coded */
|
|
int addrBrk; /* Jump here to break out of the loop */
|
|
int addrHalt; /* addrBrk for the outermost loop */
|
|
int addrCont; /* Jump here to continue with next cycle */
|
|
int iRowidReg = 0; /* Rowid is stored in this register, if not zero */
|
|
int iReleaseReg = 0; /* Temp register to free before returning */
|
|
Index *pIdx = 0; /* Index used by loop (if any) */
|
|
int iLoop; /* Iteration of constraint generator loop */
|
|
|
|
pWC = &pWInfo->sWC;
|
|
db = pParse->db;
|
|
pLoop = pLevel->pWLoop;
|
|
pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
|
|
iCur = pTabItem->iCursor;
|
|
pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
|
|
bRev = (pWInfo->revMask>>iLevel)&1;
|
|
VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
|
|
#if WHERETRACE_ENABLED /* 0x20800 */
|
|
if( sqlite3WhereTrace & 0x800 ){
|
|
sqlite3DebugPrintf("Coding level %d of %d: notReady=%llx iFrom=%d\n",
|
|
iLevel, pWInfo->nLevel, (u64)notReady, pLevel->iFrom);
|
|
sqlite3WhereLoopPrint(pLoop, pWC);
|
|
}
|
|
if( sqlite3WhereTrace & 0x20000 ){
|
|
if( iLevel==0 ){
|
|
sqlite3DebugPrintf("WHERE clause being coded:\n");
|
|
sqlite3TreeViewExpr(0, pWInfo->pWhere, 0);
|
|
}
|
|
sqlite3DebugPrintf("All WHERE-clause terms before coding:\n");
|
|
sqlite3WhereClausePrint(pWC);
|
|
}
|
|
#endif
|
|
|
|
/* Create labels for the "break" and "continue" instructions
|
|
** for the current loop. Jump to addrBrk to break out of a loop.
|
|
** Jump to cont to go immediately to the next iteration of the
|
|
** loop.
|
|
**
|
|
** When there is an IN operator, we also have a "addrNxt" label that
|
|
** means to continue with the next IN value combination. When
|
|
** there are no IN operators in the constraints, the "addrNxt" label
|
|
** is the same as "addrBrk".
|
|
*/
|
|
addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(pParse);
|
|
addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(pParse);
|
|
|
|
/* If this is the right table of a LEFT OUTER JOIN, allocate and
|
|
** initialize a memory cell that records if this table matches any
|
|
** row of the left table of the join.
|
|
*/
|
|
assert( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
|
|
|| pLevel->iFrom>0 || (pTabItem[0].fg.jointype & JT_LEFT)==0
|
|
);
|
|
if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
|
|
pLevel->iLeftJoin = ++pParse->nMem;
|
|
sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
|
|
VdbeComment((v, "init LEFT JOIN no-match flag"));
|
|
}
|
|
|
|
/* Compute a safe address to jump to if we discover that the table for
|
|
** this loop is empty and can never contribute content. */
|
|
for(j=iLevel; j>0 && pWInfo->a[j].iLeftJoin==0; j--){}
|
|
addrHalt = pWInfo->a[j].addrBrk;
|
|
|
|
/* Special case of a FROM clause subquery implemented as a co-routine */
|
|
if( pTabItem->fg.viaCoroutine ){
|
|
int regYield = pTabItem->regReturn;
|
|
sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
|
|
pLevel->p2 = sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
|
|
VdbeCoverage(v);
|
|
VdbeComment((v, "next row of %s", pTabItem->pTab->zName));
|
|
pLevel->op = OP_Goto;
|
|
}else
|
|
|
|
#ifndef SQLITE_OMIT_VIRTUALTABLE
|
|
if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
|
|
/* Case 1: The table is a virtual-table. Use the VFilter and VNext
|
|
** to access the data.
|
|
*/
|
|
int iReg; /* P3 Value for OP_VFilter */
|
|
int addrNotFound;
|
|
int nConstraint = pLoop->nLTerm;
|
|
int iIn; /* Counter for IN constraints */
|
|
|
|
iReg = sqlite3GetTempRange(pParse, nConstraint+2);
|
|
addrNotFound = pLevel->addrBrk;
|
|
for(j=0; j<nConstraint; j++){
|
|
int iTarget = iReg+j+2;
|
|
pTerm = pLoop->aLTerm[j];
|
|
if( NEVER(pTerm==0) ) continue;
|
|
if( pTerm->eOperator & WO_IN ){
|
|
codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
|
|
addrNotFound = pLevel->addrNxt;
|
|
}else{
|
|
Expr *pRight = pTerm->pExpr->pRight;
|
|
codeExprOrVector(pParse, pRight, iTarget, 1);
|
|
}
|
|
}
|
|
sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
|
|
sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
|
|
sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
|
|
pLoop->u.vtab.idxStr,
|
|
pLoop->u.vtab.needFree ? P4_DYNAMIC : P4_STATIC);
|
|
VdbeCoverage(v);
|
|
pLoop->u.vtab.needFree = 0;
|
|
pLevel->p1 = iCur;
|
|
pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;
|
|
pLevel->p2 = sqlite3VdbeCurrentAddr(v);
|
|
iIn = pLevel->u.in.nIn;
|
|
for(j=nConstraint-1; j>=0; j--){
|
|
pTerm = pLoop->aLTerm[j];
|
|
if( (pTerm->eOperator & WO_IN)!=0 ) iIn--;
|
|
if( j<16 && (pLoop->u.vtab.omitMask>>j)&1 ){
|
|
disableTerm(pLevel, pTerm);
|
|
}else if( (pTerm->eOperator & WO_IN)!=0
|
|
&& sqlite3ExprVectorSize(pTerm->pExpr->pLeft)==1
|
|
){
|
|
Expr *pCompare; /* The comparison operator */
|
|
Expr *pRight; /* RHS of the comparison */
|
|
VdbeOp *pOp; /* Opcode to access the value of the IN constraint */
|
|
|
|
/* Reload the constraint value into reg[iReg+j+2]. The same value
|
|
** was loaded into the same register prior to the OP_VFilter, but
|
|
** the xFilter implementation might have changed the datatype or
|
|
** encoding of the value in the register, so it *must* be reloaded. */
|
|
assert( pLevel->u.in.aInLoop!=0 || db->mallocFailed );
|
|
if( !db->mallocFailed ){
|
|
assert( iIn>=0 && iIn<pLevel->u.in.nIn );
|
|
pOp = sqlite3VdbeGetOp(v, pLevel->u.in.aInLoop[iIn].addrInTop);
|
|
assert( pOp->opcode==OP_Column || pOp->opcode==OP_Rowid );
|
|
assert( pOp->opcode!=OP_Column || pOp->p3==iReg+j+2 );
|
|
assert( pOp->opcode!=OP_Rowid || pOp->p2==iReg+j+2 );
|
|
testcase( pOp->opcode==OP_Rowid );
|
|
sqlite3VdbeAddOp3(v, pOp->opcode, pOp->p1, pOp->p2, pOp->p3);
|
|
}
|
|
|
|
/* Generate code that will continue to the next row if
|
|
** the IN constraint is not satisfied */
|
|
pCompare = sqlite3PExpr(pParse, TK_EQ, 0, 0);
|
|
assert( pCompare!=0 || db->mallocFailed );
|
|
if( pCompare ){
|
|
pCompare->pLeft = pTerm->pExpr->pLeft;
|
|
pCompare->pRight = pRight = sqlite3Expr(db, TK_REGISTER, 0);
|
|
if( pRight ){
|
|
pRight->iTable = iReg+j+2;
|
|
sqlite3ExprIfFalse(
|
|
pParse, pCompare, pLevel->addrCont, SQLITE_JUMPIFNULL
|
|
);
|
|
}
|
|
pCompare->pLeft = 0;
|
|
sqlite3ExprDelete(db, pCompare);
|
|
}
|
|
}
|
|
}
|
|
assert( iIn==0 || db->mallocFailed );
|
|
/* These registers need to be preserved in case there is an IN operator
|
|
** loop. So we could deallocate the registers here (and potentially
|
|
** reuse them later) if (pLoop->wsFlags & WHERE_IN_ABLE)==0. But it seems
|
|
** simpler and safer to simply not reuse the registers.
|
|
**
|
|
** sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
|
|
*/
|
|
}else
|
|
#endif /* SQLITE_OMIT_VIRTUALTABLE */
|
|
|
|
if( (pLoop->wsFlags & WHERE_IPK)!=0
|
|
&& (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
|
|
){
|
|
/* Case 2: We can directly reference a single row using an
|
|
** equality comparison against the ROWID field. Or
|
|
** we reference multiple rows using a "rowid IN (...)"
|
|
** construct.
|
|
*/
|
|
assert( pLoop->u.btree.nEq==1 );
|
|
pTerm = pLoop->aLTerm[0];
|
|
assert( pTerm!=0 );
|
|
assert( pTerm->pExpr!=0 );
|
|
testcase( pTerm->wtFlags & TERM_VIRTUAL );
|
|
iReleaseReg = ++pParse->nMem;
|
|
iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
|
|
if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
|
|
addrNxt = pLevel->addrNxt;
|
|
sqlite3VdbeAddOp3(v, OP_SeekRowid, iCur, addrNxt, iRowidReg);
|
|
VdbeCoverage(v);
|
|
pLevel->op = OP_Noop;
|
|
if( (pTerm->prereqAll & pLevel->notReady)==0 ){
|
|
pTerm->wtFlags |= TERM_CODED;
|
|
}
|
|
}else if( (pLoop->wsFlags & WHERE_IPK)!=0
|
|
&& (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
|
|
){
|
|
/* Case 3: We have an inequality comparison against the ROWID field.
|
|
*/
|
|
int testOp = OP_Noop;
|
|
int start;
|
|
int memEndValue = 0;
|
|
WhereTerm *pStart, *pEnd;
|
|
|
|
j = 0;
|
|
pStart = pEnd = 0;
|
|
if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
|
|
if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
|
|
assert( pStart!=0 || pEnd!=0 );
|
|
if( bRev ){
|
|
pTerm = pStart;
|
|
pStart = pEnd;
|
|
pEnd = pTerm;
|
|
}
|
|
codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);
|
|
if( pStart ){
|
|
Expr *pX; /* The expression that defines the start bound */
|
|
int r1, rTemp; /* Registers for holding the start boundary */
|
|
int op; /* Cursor seek operation */
|
|
|
|
/* The following constant maps TK_xx codes into corresponding
|
|
** seek opcodes. It depends on a particular ordering of TK_xx
|
|
*/
|
|
const u8 aMoveOp[] = {
|
|
/* TK_GT */ OP_SeekGT,
|
|
/* TK_LE */ OP_SeekLE,
|
|
/* TK_LT */ OP_SeekLT,
|
|
/* TK_GE */ OP_SeekGE
|
|
};
|
|
assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */
|
|
assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */
|
|
assert( TK_GE==TK_GT+3 ); /* ... is correcct. */
|
|
|
|
assert( (pStart->wtFlags & TERM_VNULL)==0 );
|
|
testcase( pStart->wtFlags & TERM_VIRTUAL );
|
|
pX = pStart->pExpr;
|
|
assert( pX!=0 );
|
|
testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
|
|
if( sqlite3ExprIsVector(pX->pRight) ){
|
|
r1 = rTemp = sqlite3GetTempReg(pParse);
|
|
codeExprOrVector(pParse, pX->pRight, r1, 1);
|
|
testcase( pX->op==TK_GT );
|
|
testcase( pX->op==TK_GE );
|
|
testcase( pX->op==TK_LT );
|
|
testcase( pX->op==TK_LE );
|
|
op = aMoveOp[((pX->op - TK_GT - 1) & 0x3) | 0x1];
|
|
assert( pX->op!=TK_GT || op==OP_SeekGE );
|
|
assert( pX->op!=TK_GE || op==OP_SeekGE );
|
|
assert( pX->op!=TK_LT || op==OP_SeekLE );
|
|
assert( pX->op!=TK_LE || op==OP_SeekLE );
|
|
}else{
|
|
r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
|
|
disableTerm(pLevel, pStart);
|
|
op = aMoveOp[(pX->op - TK_GT)];
|
|
}
|
|
sqlite3VdbeAddOp3(v, op, iCur, addrBrk, r1);
|
|
VdbeComment((v, "pk"));
|
|
VdbeCoverageIf(v, pX->op==TK_GT);
|
|
VdbeCoverageIf(v, pX->op==TK_LE);
|
|
VdbeCoverageIf(v, pX->op==TK_LT);
|
|
VdbeCoverageIf(v, pX->op==TK_GE);
|
|
sqlite3ReleaseTempReg(pParse, rTemp);
|
|
}else{
|
|
sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrHalt);
|
|
VdbeCoverageIf(v, bRev==0);
|
|
VdbeCoverageIf(v, bRev!=0);
|
|
}
|
|
if( pEnd ){
|
|
Expr *pX;
|
|
pX = pEnd->pExpr;
|
|
assert( pX!=0 );
|
|
assert( (pEnd->wtFlags & TERM_VNULL)==0 );
|
|
testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
|
|
testcase( pEnd->wtFlags & TERM_VIRTUAL );
|
|
memEndValue = ++pParse->nMem;
|
|
codeExprOrVector(pParse, pX->pRight, memEndValue, 1);
|
|
if( 0==sqlite3ExprIsVector(pX->pRight)
|
|
&& (pX->op==TK_LT || pX->op==TK_GT)
|
|
){
|
|
testOp = bRev ? OP_Le : OP_Ge;
|
|
}else{
|
|
testOp = bRev ? OP_Lt : OP_Gt;
|
|
}
|
|
if( 0==sqlite3ExprIsVector(pX->pRight) ){
|
|
disableTerm(pLevel, pEnd);
|
|
}
|
|
}
|
|
start = sqlite3VdbeCurrentAddr(v);
|
|
pLevel->op = bRev ? OP_Prev : OP_Next;
|
|
pLevel->p1 = iCur;
|
|
pLevel->p2 = start;
|
|
assert( pLevel->p5==0 );
|
|
if( testOp!=OP_Noop ){
|
|
iRowidReg = ++pParse->nMem;
|
|
sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
|
|
sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
|
|
VdbeCoverageIf(v, testOp==OP_Le);
|
|
VdbeCoverageIf(v, testOp==OP_Lt);
|
|
VdbeCoverageIf(v, testOp==OP_Ge);
|
|
VdbeCoverageIf(v, testOp==OP_Gt);
|
|
sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
|
|
}
|
|
}else if( pLoop->wsFlags & WHERE_INDEXED ){
|
|
/* Case 4: A scan using an index.
|
|
**
|
|
** The WHERE clause may contain zero or more equality
|
|
** terms ("==" or "IN" operators) that refer to the N
|
|
** left-most columns of the index. It may also contain
|
|
** inequality constraints (>, <, >= or <=) on the indexed
|
|
** column that immediately follows the N equalities. Only
|
|
** the right-most column can be an inequality - the rest must
|
|
** use the "==" and "IN" operators. For example, if the
|
|
** index is on (x,y,z), then the following clauses are all
|
|
** optimized:
|
|
**
|
|
** x=5
|
|
** x=5 AND y=10
|
|
** x=5 AND y<10
|
|
** x=5 AND y>5 AND y<10
|
|
** x=5 AND y=5 AND z<=10
|
|
**
|
|
** The z<10 term of the following cannot be used, only
|
|
** the x=5 term:
|
|
**
|
|
** x=5 AND z<10
|
|
**
|
|
** N may be zero if there are inequality constraints.
|
|
** If there are no inequality constraints, then N is at
|
|
** least one.
|
|
**
|
|
** This case is also used when there are no WHERE clause
|
|
** constraints but an index is selected anyway, in order
|
|
** to force the output order to conform to an ORDER BY.
|
|
*/
|
|
static const u8 aStartOp[] = {
|
|
0,
|
|
0,
|
|
OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */
|
|
OP_Last, /* 3: (!start_constraints && startEq && bRev) */
|
|
OP_SeekGT, /* 4: (start_constraints && !startEq && !bRev) */
|
|
OP_SeekLT, /* 5: (start_constraints && !startEq && bRev) */
|
|
OP_SeekGE, /* 6: (start_constraints && startEq && !bRev) */
|
|
OP_SeekLE /* 7: (start_constraints && startEq && bRev) */
|
|
};
|
|
static const u8 aEndOp[] = {
|
|
OP_IdxGE, /* 0: (end_constraints && !bRev && !endEq) */
|
|
OP_IdxGT, /* 1: (end_constraints && !bRev && endEq) */
|
|
OP_IdxLE, /* 2: (end_constraints && bRev && !endEq) */
|
|
OP_IdxLT, /* 3: (end_constraints && bRev && endEq) */
|
|
};
|
|
u16 nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */
|
|
u16 nBtm = pLoop->u.btree.nBtm; /* Length of BTM vector */
|
|
u16 nTop = pLoop->u.btree.nTop; /* Length of TOP vector */
|
|
int regBase; /* Base register holding constraint values */
|
|
WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
|
|
WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
|
|
int startEq; /* True if range start uses ==, >= or <= */
|
|
int endEq; /* True if range end uses ==, >= or <= */
|
|
int start_constraints; /* Start of range is constrained */
|
|
int nConstraint; /* Number of constraint terms */
|
|
int iIdxCur; /* The VDBE cursor for the index */
|
|
int nExtraReg = 0; /* Number of extra registers needed */
|
|
int op; /* Instruction opcode */
|
|
char *zStartAff; /* Affinity for start of range constraint */
|
|
char *zEndAff = 0; /* Affinity for end of range constraint */
|
|
u8 bSeekPastNull = 0; /* True to seek past initial nulls */
|
|
u8 bStopAtNull = 0; /* Add condition to terminate at NULLs */
|
|
int omitTable; /* True if we use the index only */
|
|
int regBignull = 0; /* big-null flag register */
|
|
|
|
pIdx = pLoop->u.btree.pIndex;
|
|
iIdxCur = pLevel->iIdxCur;
|
|
assert( nEq>=pLoop->nSkip );
|
|
|
|
/* Find any inequality constraint terms for the start and end
|
|
** of the range.
|
|
*/
|
|
j = nEq;
|
|
if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
|
|
pRangeStart = pLoop->aLTerm[j++];
|
|
nExtraReg = MAX(nExtraReg, pLoop->u.btree.nBtm);
|
|
/* Like optimization range constraints always occur in pairs */
|
|
assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 ||
|
|
(pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
|
|
}
|
|
if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
|
|
pRangeEnd = pLoop->aLTerm[j++];
|
|
nExtraReg = MAX(nExtraReg, pLoop->u.btree.nTop);
|
|
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
|
|
if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
|
|
assert( pRangeStart!=0 ); /* LIKE opt constraints */
|
|
assert( pRangeStart->wtFlags & TERM_LIKEOPT ); /* occur in pairs */
|
|
pLevel->iLikeRepCntr = (u32)++pParse->nMem;
|
|
sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);
|
|
VdbeComment((v, "LIKE loop counter"));
|
|
pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
|
|
/* iLikeRepCntr actually stores 2x the counter register number. The
|
|
** bottom bit indicates whether the search order is ASC or DESC. */
|
|
testcase( bRev );
|
|
testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
|
|
assert( (bRev & ~1)==0 );
|
|
pLevel->iLikeRepCntr <<=1;
|
|
pLevel->iLikeRepCntr |= bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC);
|
|
}
|
|
#endif
|
|
if( pRangeStart==0 ){
|
|
j = pIdx->aiColumn[nEq];
|
|
if( (j>=0 && pIdx->pTable->aCol[j].notNull==0) || j==XN_EXPR ){
|
|
bSeekPastNull = 1;
|
|
}
|
|
}
|
|
}
|
|
assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
|
|
|
|
/* If the WHERE_BIGNULL_SORT flag is set, then index column nEq uses
|
|
** a non-default "big-null" sort (either ASC NULLS LAST or DESC NULLS
|
|
** FIRST). In both cases separate ordered scans are made of those
|
|
** index entries for which the column is null and for those for which
|
|
** it is not. For an ASC sort, the non-NULL entries are scanned first.
|
|
** For DESC, NULL entries are scanned first.
|
|
*/
|
|
if( (pLoop->wsFlags & (WHERE_TOP_LIMIT|WHERE_BTM_LIMIT))==0
|
|
&& (pLoop->wsFlags & WHERE_BIGNULL_SORT)!=0
|
|
){
|
|
assert( bSeekPastNull==0 && nExtraReg==0 && nBtm==0 && nTop==0 );
|
|
assert( pRangeEnd==0 && pRangeStart==0 );
|
|
testcase( pLoop->nSkip>0 );
|
|
nExtraReg = 1;
|
|
bSeekPastNull = 1;
|
|
pLevel->regBignull = regBignull = ++pParse->nMem;
|
|
if( pLevel->iLeftJoin ){
|
|
sqlite3VdbeAddOp2(v, OP_Integer, 0, regBignull);
|
|
}
|
|
pLevel->addrBignull = sqlite3VdbeMakeLabel(pParse);
|
|
}
|
|
|
|
/* If we are doing a reverse order scan on an ascending index, or
|
|
** a forward order scan on a descending index, interchange the
|
|
** start and end terms (pRangeStart and pRangeEnd).
|
|
*/
|
|
if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
|
|
|| (bRev && pIdx->nKeyCol==nEq)
|
|
){
|
|
SWAP(WhereTerm *, pRangeEnd, pRangeStart);
|
|
SWAP(u8, bSeekPastNull, bStopAtNull);
|
|
SWAP(u8, nBtm, nTop);
|
|
}
|
|
|
|
/* Generate code to evaluate all constraint terms using == or IN
|
|
** and store the values of those terms in an array of registers
|
|
** starting at regBase.
|
|
*/
|
|
codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);
|
|
regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
|
|
assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
|
|
if( zStartAff && nTop ){
|
|
zEndAff = sqlite3DbStrDup(db, &zStartAff[nEq]);
|
|
}
|
|
addrNxt = (regBignull ? pLevel->addrBignull : pLevel->addrNxt);
|
|
|
|
testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
|
|
testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
|
|
testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
|
|
testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
|
|
startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
|
|
endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
|
|
start_constraints = pRangeStart || nEq>0;
|
|
|
|
/* Seek the index cursor to the start of the range. */
|
|
nConstraint = nEq;
|
|
if( pRangeStart ){
|
|
Expr *pRight = pRangeStart->pExpr->pRight;
|
|
codeExprOrVector(pParse, pRight, regBase+nEq, nBtm);
|
|
whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
|
|
if( (pRangeStart->wtFlags & TERM_VNULL)==0
|
|
&& sqlite3ExprCanBeNull(pRight)
|
|
){
|
|
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
|
|
VdbeCoverage(v);
|
|
}
|
|
if( zStartAff ){
|
|
updateRangeAffinityStr(pRight, nBtm, &zStartAff[nEq]);
|
|
}
|
|
nConstraint += nBtm;
|
|
testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
|
|
if( sqlite3ExprIsVector(pRight)==0 ){
|
|
disableTerm(pLevel, pRangeStart);
|
|
}else{
|
|
startEq = 1;
|
|
}
|
|
bSeekPastNull = 0;
|
|
}else if( bSeekPastNull ){
|
|
startEq = 0;
|
|
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
|
|
start_constraints = 1;
|
|
nConstraint++;
|
|
}else if( regBignull ){
|
|
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
|
|
start_constraints = 1;
|
|
nConstraint++;
|
|
}
|
|
codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
|
|
if( pLoop->nSkip>0 && nConstraint==pLoop->nSkip ){
|
|
/* The skip-scan logic inside the call to codeAllEqualityConstraints()
|
|
** above has already left the cursor sitting on the correct row,
|
|
** so no further seeking is needed */
|
|
}else{
|
|
if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){
|
|
sqlite3VdbeAddOp1(v, OP_SeekHit, iIdxCur);
|
|
}
|
|
if( regBignull ){
|
|
sqlite3VdbeAddOp2(v, OP_Integer, 1, regBignull);
|
|
VdbeComment((v, "NULL-scan pass ctr"));
|
|
}
|
|
|
|
op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
|
|
assert( op!=0 );
|
|
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
|
|
VdbeCoverage(v);
|
|
VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind );
|
|
VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last );
|
|
VdbeCoverageIf(v, op==OP_SeekGT); testcase( op==OP_SeekGT );
|
|
VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE );
|
|
VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE );
|
|
VdbeCoverageIf(v, op==OP_SeekLT); testcase( op==OP_SeekLT );
|
|
|
|
assert( bSeekPastNull==0 || bStopAtNull==0 );
|
|
if( regBignull ){
|
|
assert( bSeekPastNull==1 || bStopAtNull==1 );
|
|
assert( bSeekPastNull==!bStopAtNull );
|
|
assert( bStopAtNull==startEq );
|
|
sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+2);
|
|
op = aStartOp[(nConstraint>1)*4 + 2 + bRev];
|
|
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase,
|
|
nConstraint-startEq);
|
|
VdbeCoverage(v);
|
|
VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind );
|
|
VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last );
|
|
VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE );
|
|
VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE );
|
|
assert( op==OP_Rewind || op==OP_Last || op==OP_SeekGE || op==OP_SeekLE);
|
|
}
|
|
}
|
|
|
|
/* Load the value for the inequality constraint at the end of the
|
|
** range (if any).
|
|
*/
|
|
nConstraint = nEq;
|
|
if( pRangeEnd ){
|
|
Expr *pRight = pRangeEnd->pExpr->pRight;
|
|
codeExprOrVector(pParse, pRight, regBase+nEq, nTop);
|
|
whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
|
|
if( (pRangeEnd->wtFlags & TERM_VNULL)==0
|
|
&& sqlite3ExprCanBeNull(pRight)
|
|
){
|
|
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
|
|
VdbeCoverage(v);
|
|
}
|
|
if( zEndAff ){
|
|
updateRangeAffinityStr(pRight, nTop, zEndAff);
|
|
codeApplyAffinity(pParse, regBase+nEq, nTop, zEndAff);
|
|
}else{
|
|
assert( pParse->db->mallocFailed );
|
|
}
|
|
nConstraint += nTop;
|
|
testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
|
|
|
|
if( sqlite3ExprIsVector(pRight)==0 ){
|
|
disableTerm(pLevel, pRangeEnd);
|
|
}else{
|
|
endEq = 1;
|
|
}
|
|
}else if( bStopAtNull ){
|
|
if( regBignull==0 ){
|
|
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
|
|
endEq = 0;
|
|
}
|
|
nConstraint++;
|
|
}
|
|
sqlite3DbFree(db, zStartAff);
|
|
sqlite3DbFree(db, zEndAff);
|
|
|
|
/* Top of the loop body */
|
|
pLevel->p2 = sqlite3VdbeCurrentAddr(v);
|
|
|
|
/* Check if the index cursor is past the end of the range. */
|
|
if( nConstraint ){
|
|
if( regBignull ){
|
|
/* Except, skip the end-of-range check while doing the NULL-scan */
|
|
sqlite3VdbeAddOp2(v, OP_IfNot, regBignull, sqlite3VdbeCurrentAddr(v)+3);
|
|
VdbeComment((v, "If NULL-scan 2nd pass"));
|
|
VdbeCoverage(v);
|
|
}
|
|
op = aEndOp[bRev*2 + endEq];
|
|
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
|
|
testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
|
|
testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
|
|
testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
|
|
testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
|
|
}
|
|
if( regBignull ){
|
|
/* During a NULL-scan, check to see if we have reached the end of
|
|
** the NULLs */
|
|
assert( bSeekPastNull==!bStopAtNull );
|
|
assert( bSeekPastNull+bStopAtNull==1 );
|
|
assert( nConstraint+bSeekPastNull>0 );
|
|
sqlite3VdbeAddOp2(v, OP_If, regBignull, sqlite3VdbeCurrentAddr(v)+2);
|
|
VdbeComment((v, "If NULL-scan 1st pass"));
|
|
VdbeCoverage(v);
|
|
op = aEndOp[bRev*2 + bSeekPastNull];
|
|
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase,
|
|
nConstraint+bSeekPastNull);
|
|
testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
|
|
testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
|
|
testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
|
|
testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
|
|
}
|
|
|
|
if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){
|
|
sqlite3VdbeAddOp2(v, OP_SeekHit, iIdxCur, 1);
|
|
}
|
|
|
|
/* Seek the table cursor, if required */
|
|
omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0
|
|
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0;
|
|
if( omitTable ){
|
|
/* pIdx is a covering index. No need to access the main table. */
|
|
}else if( HasRowid(pIdx->pTable) ){
|
|
if( (pWInfo->wctrlFlags & WHERE_SEEK_TABLE)
|
|
|| ( (pWInfo->wctrlFlags & WHERE_SEEK_UNIQ_TABLE)!=0
|
|
&& (pWInfo->eOnePass==ONEPASS_SINGLE || pLoop->nLTerm==0) )
|
|
){
|
|
iRowidReg = ++pParse->nMem;
|
|
sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
|
|
sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
|
|
VdbeCoverage(v);
|
|
}else{
|
|
codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);
|
|
}
|
|
}else if( iCur!=iIdxCur ){
|
|
Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
|
|
iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
|
|
for(j=0; j<pPk->nKeyCol; j++){
|
|
k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[j]);
|
|
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
|
|
}
|
|
sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
|
|
iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
|
|
}
|
|
|
|
if( pLevel->iLeftJoin==0 ){
|
|
/* If pIdx is an index on one or more expressions, then look through
|
|
** all the expressions in pWInfo and try to transform matching expressions
|
|
** into reference to index columns. Also attempt to translate references
|
|
** to virtual columns in the table into references to (stored) columns
|
|
** of the index.
|
|
**
|
|
** Do not do this for the RHS of a LEFT JOIN. This is because the
|
|
** expression may be evaluated after OP_NullRow has been executed on
|
|
** the cursor. In this case it is important to do the full evaluation,
|
|
** as the result of the expression may not be NULL, even if all table
|
|
** column values are. https://www.sqlite.org/src/info/7fa8049685b50b5a
|
|
**
|
|
** Also, do not do this when processing one index an a multi-index
|
|
** OR clause, since the transformation will become invalid once we
|
|
** move forward to the next index.
|
|
** https://sqlite.org/src/info/4e8e4857d32d401f
|
|
*/
|
|
if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){
|
|
whereIndexExprTrans(pIdx, iCur, iIdxCur, pWInfo);
|
|
}
|
|
|
|
/* If a partial index is driving the loop, try to eliminate WHERE clause
|
|
** terms from the query that must be true due to the WHERE clause of
|
|
** the partial index.
|
|
**
|
|
** 2019-11-02 ticket 623eff57e76d45f6: This optimization does not work
|
|
** for a LEFT JOIN.
|
|
*/
|
|
if( pIdx->pPartIdxWhere ){
|
|
whereApplyPartialIndexConstraints(pIdx->pPartIdxWhere, iCur, pWC);
|
|
}
|
|
}else{
|
|
testcase( pIdx->pPartIdxWhere );
|
|
/* The following assert() is not a requirement, merely an observation:
|
|
** The OR-optimization doesn't work for the right hand table of
|
|
** a LEFT JOIN: */
|
|
assert( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0 );
|
|
}
|
|
|
|
/* Record the instruction used to terminate the loop. */
|
|
if( pLoop->wsFlags & WHERE_ONEROW ){
|
|
pLevel->op = OP_Noop;
|
|
}else if( bRev ){
|
|
pLevel->op = OP_Prev;
|
|
}else{
|
|
pLevel->op = OP_Next;
|
|
}
|
|
pLevel->p1 = iIdxCur;
|
|
pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
|
|
if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
|
|
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
|
|
}else{
|
|
assert( pLevel->p5==0 );
|
|
}
|
|
if( omitTable ) pIdx = 0;
|
|
}else
|
|
|
|
#ifndef SQLITE_OMIT_OR_OPTIMIZATION
|
|
if( pLoop->wsFlags & WHERE_MULTI_OR ){
|
|
/* Case 5: Two or more separately indexed terms connected by OR
|
|
**
|
|
** Example:
|
|
**
|
|
** CREATE TABLE t1(a,b,c,d);
|
|
** CREATE INDEX i1 ON t1(a);
|
|
** CREATE INDEX i2 ON t1(b);
|
|
** CREATE INDEX i3 ON t1(c);
|
|
**
|
|
** SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
|
|
**
|
|
** In the example, there are three indexed terms connected by OR.
|
|
** The top of the loop looks like this:
|
|
**
|
|
** Null 1 # Zero the rowset in reg 1
|
|
**
|
|
** Then, for each indexed term, the following. The arguments to
|
|
** RowSetTest are such that the rowid of the current row is inserted
|
|
** into the RowSet. If it is already present, control skips the
|
|
** Gosub opcode and jumps straight to the code generated by WhereEnd().
|
|
**
|
|
** sqlite3WhereBegin(<term>)
|
|
** RowSetTest # Insert rowid into rowset
|
|
** Gosub 2 A
|
|
** sqlite3WhereEnd()
|
|
**
|
|
** Following the above, code to terminate the loop. Label A, the target
|
|
** of the Gosub above, jumps to the instruction right after the Goto.
|
|
**
|
|
** Null 1 # Zero the rowset in reg 1
|
|
** Goto B # The loop is finished.
|
|
**
|
|
** A: <loop body> # Return data, whatever.
|
|
**
|
|
** Return 2 # Jump back to the Gosub
|
|
**
|
|
** B: <after the loop>
|
|
**
|
|
** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
|
|
** use an ephemeral index instead of a RowSet to record the primary
|
|
** keys of the rows we have already seen.
|
|
**
|
|
*/
|
|
WhereClause *pOrWc; /* The OR-clause broken out into subterms */
|
|
SrcList *pOrTab; /* Shortened table list or OR-clause generation */
|
|
Index *pCov = 0; /* Potential covering index (or NULL) */
|
|
int iCovCur = pParse->nTab++; /* Cursor used for index scans (if any) */
|
|
|
|
int regReturn = ++pParse->nMem; /* Register used with OP_Gosub */
|
|
int regRowset = 0; /* Register for RowSet object */
|
|
int regRowid = 0; /* Register holding rowid */
|
|
int iLoopBody = sqlite3VdbeMakeLabel(pParse);/* Start of loop body */
|
|
int iRetInit; /* Address of regReturn init */
|
|
int untestedTerms = 0; /* Some terms not completely tested */
|
|
int ii; /* Loop counter */
|
|
u16 wctrlFlags; /* Flags for sub-WHERE clause */
|
|
Expr *pAndExpr = 0; /* An ".. AND (...)" expression */
|
|
Table *pTab = pTabItem->pTab;
|
|
|
|
pTerm = pLoop->aLTerm[0];
|
|
assert( pTerm!=0 );
|
|
assert( pTerm->eOperator & WO_OR );
|
|
assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
|
|
pOrWc = &pTerm->u.pOrInfo->wc;
|
|
pLevel->op = OP_Return;
|
|
pLevel->p1 = regReturn;
|
|
|
|
/* Set up a new SrcList in pOrTab containing the table being scanned
|
|
** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
|
|
** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
|
|
*/
|
|
if( pWInfo->nLevel>1 ){
|
|
int nNotReady; /* The number of notReady tables */
|
|
struct SrcList_item *origSrc; /* Original list of tables */
|
|
nNotReady = pWInfo->nLevel - iLevel - 1;
|
|
pOrTab = sqlite3StackAllocRaw(db,
|
|
sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
|
|
if( pOrTab==0 ) return notReady;
|
|
pOrTab->nAlloc = (u8)(nNotReady + 1);
|
|
pOrTab->nSrc = pOrTab->nAlloc;
|
|
memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
|
|
origSrc = pWInfo->pTabList->a;
|
|
for(k=1; k<=nNotReady; k++){
|
|
memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
|
|
}
|
|
}else{
|
|
pOrTab = pWInfo->pTabList;
|
|
}
|
|
|
|
/* Initialize the rowset register to contain NULL. An SQL NULL is
|
|
** equivalent to an empty rowset. Or, create an ephemeral index
|
|
** capable of holding primary keys in the case of a WITHOUT ROWID.
|
|
**
|
|
** Also initialize regReturn to contain the address of the instruction
|
|
** immediately following the OP_Return at the bottom of the loop. This
|
|
** is required in a few obscure LEFT JOIN cases where control jumps
|
|
** over the top of the loop into the body of it. In this case the
|
|
** correct response for the end-of-loop code (the OP_Return) is to
|
|
** fall through to the next instruction, just as an OP_Next does if
|
|
** called on an uninitialized cursor.
|
|
*/
|
|
if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
|
|
if( HasRowid(pTab) ){
|
|
regRowset = ++pParse->nMem;
|
|
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
|
|
}else{
|
|
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
|
|
regRowset = pParse->nTab++;
|
|
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
|
|
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
|
|
}
|
|
regRowid = ++pParse->nMem;
|
|
}
|
|
iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
|
|
|
|
/* If the original WHERE clause is z of the form: (x1 OR x2 OR ...) AND y
|
|
** Then for every term xN, evaluate as the subexpression: xN AND z
|
|
** That way, terms in y that are factored into the disjunction will
|
|
** be picked up by the recursive calls to sqlite3WhereBegin() below.
|
|
**
|
|
** Actually, each subexpression is converted to "xN AND w" where w is
|
|
** the "interesting" terms of z - terms that did not originate in the
|
|
** ON or USING clause of a LEFT JOIN, and terms that are usable as
|
|
** indices.
|
|
**
|
|
** This optimization also only applies if the (x1 OR x2 OR ...) term
|
|
** is not contained in the ON clause of a LEFT JOIN.
|
|
** See ticket http://www.sqlite.org/src/info/f2369304e4
|
|
*/
|
|
if( pWC->nTerm>1 ){
|
|
int iTerm;
|
|
for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
|
|
Expr *pExpr = pWC->a[iTerm].pExpr;
|
|
if( &pWC->a[iTerm] == pTerm ) continue;
|
|
testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
|
|
testcase( pWC->a[iTerm].wtFlags & TERM_CODED );
|
|
if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;
|
|
if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
|
|
testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
|
|
pExpr = sqlite3ExprDup(db, pExpr, 0);
|
|
pAndExpr = sqlite3ExprAnd(pParse, pAndExpr, pExpr);
|
|
}
|
|
if( pAndExpr ){
|
|
/* The extra 0x10000 bit on the opcode is masked off and does not
|
|
** become part of the new Expr.op. However, it does make the
|
|
** op==TK_AND comparison inside of sqlite3PExpr() false, and this
|
|
** prevents sqlite3PExpr() from implementing AND short-circuit
|
|
** optimization, which we do not want here. */
|
|
pAndExpr = sqlite3PExpr(pParse, TK_AND|0x10000, 0, pAndExpr);
|
|
}
|
|
}
|
|
|
|
/* Run a separate WHERE clause for each term of the OR clause. After
|
|
** eliminating duplicates from other WHERE clauses, the action for each
|
|
** sub-WHERE clause is to to invoke the main loop body as a subroutine.
|
|
*/
|
|
wctrlFlags = WHERE_OR_SUBCLAUSE | (pWInfo->wctrlFlags & WHERE_SEEK_TABLE);
|
|
ExplainQueryPlan((pParse, 1, "MULTI-INDEX OR"));
|
|
for(ii=0; ii<pOrWc->nTerm; ii++){
|
|
WhereTerm *pOrTerm = &pOrWc->a[ii];
|
|
if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
|
|
WhereInfo *pSubWInfo; /* Info for single OR-term scan */
|
|
Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
|
|
int jmp1 = 0; /* Address of jump operation */
|
|
testcase( (pTabItem[0].fg.jointype & JT_LEFT)!=0
|
|
&& !ExprHasProperty(pOrExpr, EP_FromJoin)
|
|
); /* See TH3 vtab25.400 and ticket 614b25314c766238 */
|
|
if( pAndExpr ){
|
|
pAndExpr->pLeft = pOrExpr;
|
|
pOrExpr = pAndExpr;
|
|
}
|
|
/* Loop through table entries that match term pOrTerm. */
|
|
ExplainQueryPlan((pParse, 1, "INDEX %d", ii+1));
|
|
WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
|
|
pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
|
|
wctrlFlags, iCovCur);
|
|
assert( pSubWInfo || pParse->nErr || db->mallocFailed );
|
|
if( pSubWInfo ){
|
|
WhereLoop *pSubLoop;
|
|
int addrExplain = sqlite3WhereExplainOneScan(
|
|
pParse, pOrTab, &pSubWInfo->a[0], 0
|
|
);
|
|
sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
|
|
|
|
/* This is the sub-WHERE clause body. First skip over
|
|
** duplicate rows from prior sub-WHERE clauses, and record the
|
|
** rowid (or PRIMARY KEY) for the current row so that the same
|
|
** row will be skipped in subsequent sub-WHERE clauses.
|
|
*/
|
|
if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
|
|
int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
|
|
if( HasRowid(pTab) ){
|
|
sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, -1, regRowid);
|
|
jmp1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0,
|
|
regRowid, iSet);
|
|
VdbeCoverage(v);
|
|
}else{
|
|
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
|
|
int nPk = pPk->nKeyCol;
|
|
int iPk;
|
|
int r;
|
|
|
|
/* Read the PK into an array of temp registers. */
|
|
r = sqlite3GetTempRange(pParse, nPk);
|
|
for(iPk=0; iPk<nPk; iPk++){
|
|
int iCol = pPk->aiColumn[iPk];
|
|
sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol,r+iPk);
|
|
}
|
|
|
|
/* Check if the temp table already contains this key. If so,
|
|
** the row has already been included in the result set and
|
|
** can be ignored (by jumping past the Gosub below). Otherwise,
|
|
** insert the key into the temp table and proceed with processing
|
|
** the row.
|
|
**
|
|
** Use some of the same optimizations as OP_RowSetTest: If iSet
|
|
** is zero, assume that the key cannot already be present in
|
|
** the temp table. And if iSet is -1, assume that there is no
|
|
** need to insert the key into the temp table, as it will never
|
|
** be tested for. */
|
|
if( iSet ){
|
|
jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
|
|
VdbeCoverage(v);
|
|
}
|
|
if( iSet>=0 ){
|
|
sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
|
|
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, regRowset, regRowid,
|
|
r, nPk);
|
|
if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
|
|
}
|
|
|
|
/* Release the array of temp registers */
|
|
sqlite3ReleaseTempRange(pParse, r, nPk);
|
|
}
|
|
}
|
|
|
|
/* Invoke the main loop body as a subroutine */
|
|
sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
|
|
|
|
/* Jump here (skipping the main loop body subroutine) if the
|
|
** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
|
|
if( jmp1 ) sqlite3VdbeJumpHere(v, jmp1);
|
|
|
|
/* The pSubWInfo->untestedTerms flag means that this OR term
|
|
** contained one or more AND term from a notReady table. The
|
|
** terms from the notReady table could not be tested and will
|
|
** need to be tested later.
|
|
*/
|
|
if( pSubWInfo->untestedTerms ) untestedTerms = 1;
|
|
|
|
/* If all of the OR-connected terms are optimized using the same
|
|
** index, and the index is opened using the same cursor number
|
|
** by each call to sqlite3WhereBegin() made by this loop, it may
|
|
** be possible to use that index as a covering index.
|
|
**
|
|
** If the call to sqlite3WhereBegin() above resulted in a scan that
|
|
** uses an index, and this is either the first OR-connected term
|
|
** processed or the index is the same as that used by all previous
|
|
** terms, set pCov to the candidate covering index. Otherwise, set
|
|
** pCov to NULL to indicate that no candidate covering index will
|
|
** be available.
|
|
*/
|
|
pSubLoop = pSubWInfo->a[0].pWLoop;
|
|
assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
|
|
if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
|
|
&& (ii==0 || pSubLoop->u.btree.pIndex==pCov)
|
|
&& (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
|
|
){
|
|
assert( pSubWInfo->a[0].iIdxCur==iCovCur );
|
|
pCov = pSubLoop->u.btree.pIndex;
|
|
}else{
|
|
pCov = 0;
|
|
}
|
|
|
|
/* Finish the loop through table entries that match term pOrTerm. */
|
|
sqlite3WhereEnd(pSubWInfo);
|
|
ExplainQueryPlanPop(pParse);
|
|
}
|
|
}
|
|
}
|
|
ExplainQueryPlanPop(pParse);
|
|
pLevel->u.pCovidx = pCov;
|
|
if( pCov ) pLevel->iIdxCur = iCovCur;
|
|
if( pAndExpr ){
|
|
pAndExpr->pLeft = 0;
|
|
sqlite3ExprDelete(db, pAndExpr);
|
|
}
|
|
sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
|
|
sqlite3VdbeGoto(v, pLevel->addrBrk);
|
|
sqlite3VdbeResolveLabel(v, iLoopBody);
|
|
|
|
if( pWInfo->nLevel>1 ){ sqlite3StackFree(db, pOrTab); }
|
|
if( !untestedTerms ) disableTerm(pLevel, pTerm);
|
|
}else
|
|
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
|
|
|
|
{
|
|
/* Case 6: There is no usable index. We must do a complete
|
|
** scan of the entire table.
|
|
*/
|
|
static const u8 aStep[] = { OP_Next, OP_Prev };
|
|
static const u8 aStart[] = { OP_Rewind, OP_Last };
|
|
assert( bRev==0 || bRev==1 );
|
|
if( pTabItem->fg.isRecursive ){
|
|
/* Tables marked isRecursive have only a single row that is stored in
|
|
** a pseudo-cursor. No need to Rewind or Next such cursors. */
|
|
pLevel->op = OP_Noop;
|
|
}else{
|
|
codeCursorHint(pTabItem, pWInfo, pLevel, 0);
|
|
pLevel->op = aStep[bRev];
|
|
pLevel->p1 = iCur;
|
|
pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrHalt);
|
|
VdbeCoverageIf(v, bRev==0);
|
|
VdbeCoverageIf(v, bRev!=0);
|
|
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
|
|
}
|
|
}
|
|
|
|
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
|
|
pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
|
|
#endif
|
|
|
|
/* Insert code to test every subexpression that can be completely
|
|
** computed using the current set of tables.
|
|
**
|
|
** This loop may run between one and three times, depending on the
|
|
** constraints to be generated. The value of stack variable iLoop
|
|
** determines the constraints coded by each iteration, as follows:
|
|
**
|
|
** iLoop==1: Code only expressions that are entirely covered by pIdx.
|
|
** iLoop==2: Code remaining expressions that do not contain correlated
|
|
** sub-queries.
|
|
** iLoop==3: Code all remaining expressions.
|
|
**
|
|
** An effort is made to skip unnecessary iterations of the loop.
|
|
*/
|
|
iLoop = (pIdx ? 1 : 2);
|
|
do{
|
|
int iNext = 0; /* Next value for iLoop */
|
|
for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
|
|
Expr *pE;
|
|
int skipLikeAddr = 0;
|
|
testcase( pTerm->wtFlags & TERM_VIRTUAL );
|
|
testcase( pTerm->wtFlags & TERM_CODED );
|
|
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
|
|
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
|
|
testcase( pWInfo->untestedTerms==0
|
|
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
|
|
pWInfo->untestedTerms = 1;
|
|
continue;
|
|
}
|
|
pE = pTerm->pExpr;
|
|
assert( pE!=0 );
|
|
if( (pTabItem->fg.jointype&JT_LEFT) && !ExprHasProperty(pE,EP_FromJoin) ){
|
|
continue;
|
|
}
|
|
|
|
if( iLoop==1 && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){
|
|
iNext = 2;
|
|
continue;
|
|
}
|
|
if( iLoop<3 && (pTerm->wtFlags & TERM_VARSELECT) ){
|
|
if( iNext==0 ) iNext = 3;
|
|
continue;
|
|
}
|
|
|
|
if( (pTerm->wtFlags & TERM_LIKECOND)!=0 ){
|
|
/* If the TERM_LIKECOND flag is set, that means that the range search
|
|
** is sufficient to guarantee that the LIKE operator is true, so we
|
|
** can skip the call to the like(A,B) function. But this only works
|
|
** for strings. So do not skip the call to the function on the pass
|
|
** that compares BLOBs. */
|
|
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
|
|
continue;
|
|
#else
|
|
u32 x = pLevel->iLikeRepCntr;
|
|
if( x>0 ){
|
|
skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)?OP_IfNot:OP_If,(int)(x>>1));
|
|
VdbeCoverageIf(v, (x&1)==1);
|
|
VdbeCoverageIf(v, (x&1)==0);
|
|
}
|
|
#endif
|
|
}
|
|
#ifdef WHERETRACE_ENABLED /* 0xffff */
|
|
if( sqlite3WhereTrace ){
|
|
VdbeNoopComment((v, "WhereTerm[%d] (%p) priority=%d",
|
|
pWC->nTerm-j, pTerm, iLoop));
|
|
}
|
|
if( sqlite3WhereTrace & 0x800 ){
|
|
sqlite3DebugPrintf("Coding auxiliary constraint:\n");
|
|
sqlite3WhereTermPrint(pTerm, pWC->nTerm-j);
|
|
}
|
|
#endif
|
|
sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
|
|
if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
|
|
pTerm->wtFlags |= TERM_CODED;
|
|
}
|
|
iLoop = iNext;
|
|
}while( iLoop>0 );
|
|
|
|
/* Insert code to test for implied constraints based on transitivity
|
|
** of the "==" operator.
|
|
**
|
|
** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
|
|
** and we are coding the t1 loop and the t2 loop has not yet coded,
|
|
** then we cannot use the "t1.a=t2.b" constraint, but we can code
|
|
** the implied "t1.a=123" constraint.
|
|
*/
|
|
for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
|
|
Expr *pE, sEAlt;
|
|
WhereTerm *pAlt;
|
|
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
|
|
if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
|
|
if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
|
|
if( pTerm->leftCursor!=iCur ) continue;
|
|
if( pTabItem->fg.jointype & JT_LEFT ) continue;
|
|
pE = pTerm->pExpr;
|
|
#ifdef WHERETRACE_ENABLED /* 0x800 */
|
|
if( sqlite3WhereTrace & 0x800 ){
|
|
sqlite3DebugPrintf("Coding transitive constraint:\n");
|
|
sqlite3WhereTermPrint(pTerm, pWC->nTerm-j);
|
|
}
|
|
#endif
|
|
assert( !ExprHasProperty(pE, EP_FromJoin) );
|
|
assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
|
|
pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.leftColumn, notReady,
|
|
WO_EQ|WO_IN|WO_IS, 0);
|
|
if( pAlt==0 ) continue;
|
|
if( pAlt->wtFlags & (TERM_CODED) ) continue;
|
|
if( (pAlt->eOperator & WO_IN)
|
|
&& (pAlt->pExpr->flags & EP_xIsSelect)
|
|
&& (pAlt->pExpr->x.pSelect->pEList->nExpr>1)
|
|
){
|
|
continue;
|
|
}
|
|
testcase( pAlt->eOperator & WO_EQ );
|
|
testcase( pAlt->eOperator & WO_IS );
|
|
testcase( pAlt->eOperator & WO_IN );
|
|
VdbeModuleComment((v, "begin transitive constraint"));
|
|
sEAlt = *pAlt->pExpr;
|
|
sEAlt.pLeft = pE->pLeft;
|
|
sqlite3ExprIfFalse(pParse, &sEAlt, addrCont, SQLITE_JUMPIFNULL);
|
|
}
|
|
|
|
/* For a LEFT OUTER JOIN, generate code that will record the fact that
|
|
** at least one row of the right table has matched the left table.
|
|
*/
|
|
if( pLevel->iLeftJoin ){
|
|
pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
|
|
sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
|
|
VdbeComment((v, "record LEFT JOIN hit"));
|
|
for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
|
|
testcase( pTerm->wtFlags & TERM_VIRTUAL );
|
|
testcase( pTerm->wtFlags & TERM_CODED );
|
|
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
|
|
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
|
|
assert( pWInfo->untestedTerms );
|
|
continue;
|
|
}
|
|
assert( pTerm->pExpr );
|
|
sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
|
|
pTerm->wtFlags |= TERM_CODED;
|
|
}
|
|
}
|
|
|
|
#if WHERETRACE_ENABLED /* 0x20800 */
|
|
if( sqlite3WhereTrace & 0x20000 ){
|
|
sqlite3DebugPrintf("All WHERE-clause terms after coding level %d:\n",
|
|
iLevel);
|
|
sqlite3WhereClausePrint(pWC);
|
|
}
|
|
if( sqlite3WhereTrace & 0x800 ){
|
|
sqlite3DebugPrintf("End Coding level %d: notReady=%llx\n",
|
|
iLevel, (u64)pLevel->notReady);
|
|
}
|
|
#endif
|
|
return pLevel->notReady;
|
|
}
|