Add the TK_IF_NULL_ROW opcode to deal with non-NULL result columns in the

result set of a view or subquery on the RHS of a LEFT JOIN that gets flattened.

FossilOrigin-Name: 3a5860d86fadcf924316707918bf283d26c53b1473e5e67f5cff59d18c2a7742
This commit is contained in:
drh 2017-04-14 19:03:10 +00:00
parent 399c7e21e4
commit 31d6fd5507
9 changed files with 83 additions and 47 deletions

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@ -1,5 +1,5 @@
C An\sinitial\sattempt\sto\soptimize\sVIEWs\sthat\soccur\sas\sthe\sright\soperand\sof\sa\nLEFT\sJOIN.\s\sThis\sparticular\scheck-in\sdoes\snot\swork\scorrectly\sbecause\sit\sdoes\nnot\sdeal\swith\sthe\scase\sof\scolumns\sin\sthe\sVIEW\sthat\sreturn\snon-NULL\seven\swhen\nall\scolumns\sin\sthe\stable\sof\sthe\sVIEW\sare\sNULL\sbecause\sof\sthe\sLEFT\sJOIN.
D 2017-04-14T17:18:45.647
C Add\sthe\sTK_IF_NULL_ROW\sopcode\sto\sdeal\swith\snon-NULL\sresult\scolumns\sin\sthe\nresult\sset\sof\sa\sview\sor\ssubquery\son\sthe\sRHS\sof\sa\sLEFT\sJOIN\sthat\sgets\sflattened.
D 2017-04-14T19:03:10.224
F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
F Makefile.msc 6a8c838220f7c00820e1fc0ac1bccaaa8e5676067e1dbfa1bafa7a4ffecf8ae6
@ -354,7 +354,7 @@ F src/ctime.c 47d91a25ad8f199a71a5b1b7b169d6dd0d6e98c5719eca801568798743d1161c
F src/date.c ee676e7694dfadbdd2fde1a258a71be8360ba5ae
F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
F src/delete.c 0d9d5549d42e79ce4d82ff1db1e6c81e36d2f67c
F src/expr.c f6914d6d06c9a1e488f49cd51a0ef12d8073231e9c1a25c4c821262686cadcbf
F src/expr.c f10e35dc50be4c8f82eb99bf5d8530229d1d60957cc3c9473ffe584d0444087c
F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
F src/fkey.c db65492ae549c3b548c9ef1f279ce1684f1c473b116e1c56a90878cd5dcf968d
F src/func.c 9d52522cc8ae7f5cdadfe14594262f1618bc1f86083c4cd6da861b4cf5af6174
@ -390,7 +390,7 @@ F src/os_win.c 2a6c73eef01c51a048cc4ddccd57f981afbec18a
F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
F src/pager.c ff1232b3088a39806035ecfac4fffeb22717d80b
F src/pager.h f2a99646c5533ffe11afa43e9e0bea74054e4efa
F src/parse.y 48b03113704ee8bd78ee6996d81de7fbee22e105
F src/parse.y 0513387ce02fea97897d8caef82d45f347818593f24f1bdc48e0c530a8af122d
F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
F src/pcache.h 2cedcd8407eb23017d92790b112186886e179490
F src/pcache1.c 1195a21fe28e223e024f900b2011e80df53793f0356a24caace4188b098540dc
@ -401,7 +401,7 @@ F src/printf.c 8757834f1b54dae512fb25eb1acc8e94a0d15dd2290b58f2563f65973265adb2
F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
F src/resolve.c 3e518b962d932a997fae373366880fc028c75706
F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
F src/select.c 52b29bdeaa4cf317a981b6e8d0a15ec9c16372a738ede51c2a285c03fc69d036
F src/select.c bf8ab605e49717c222136380453cfb7eda564f8e500d5ff6a01341ea59fefe80
F src/shell.c 70f4957b988572315e97c56941fdc81fd35907fee36b7b2e7be5ec4c7e9d065d
F src/sqlite.h.in 40233103e3e4e10f8a63523498d0259d232e42aba478e2d3fb914799185aced6
F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@ -462,13 +462,13 @@ F src/test_windirent.h 5d67483a55442e31e1bde0f4a230e6e932ad5906
F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
F src/tokenize.c 1003d6d90c6783206c711f0a9397656fa5b055209f4d092caa43bb3bf5215db5
F src/treeview.c b92d57c1ac59f4a3f6b189506921a2b48098f6f4d6afd0b715bc2815ef6af092
F src/treeview.c 6cf8d7fe9e63fae57dad1bb57f6615e14eac0c527e43d868e805042cae8ed1f7
F src/trigger.c c9f0810043b265724fdb1bdd466894f984dfc182
F src/update.c c443935c652af9365e033f756550b5032d02e1b06eb2cb890ed7511ae0c051dc
F src/utf.c 699001c79f28e48e9bcdf8a463da029ea660540c
F src/util.c ca8440ede81e155d15cff7c101654f60b55a9ae6
F src/vacuum.c 1fe4555cd8c9b263afb85b5b4ee3a4a4181ad569
F src/vdbe.c 808fda3d50f544120d27c731449b524b4ec8f8b0f734b228831078f0ba53ecb9
F src/vdbe.c ef0fd44a2b4f70e006d050a98c6f563e19293d683975a95287668340764f99f1
F src/vdbe.h f7d1456e28875c2dcb964056589b5b7149ab7edf39edeca801596a39bb3d3848
F src/vdbeInt.h c070bc5c8b913bda0ceaa995cd4d939ded5e4fc96cf7c3c1c602d41b871f8ade
F src/vdbeapi.c 5b08d82592bcff4470601fe78aaabebd50837860
@ -482,7 +482,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
F src/wal.c 40c543f0a2195d1b0dc88ef12142bea690009344
F src/wal.h 06b2a0b599cc0f53ea97f497cf8c6b758c999f71
F src/walker.c b71a992b413b3a022572eccf29ef4b4890223791
F src/where.c 1d14e18f32231fa7969e718e7b60ef749b0065e2a7e1b6b00883b20732d280f1
F src/where.c e02cbd8a830d36e48b1640d0c7b49526322e35fa800c729c17c5d63712a01275
F src/whereInt.h 7a21ef633e26acbf46df04add2eba6e0a2100c78dc5879049e93f981fc3344df
F src/wherecode.c 943e32e9dccd0af802e0683ae11071c8bd808364e5908a5fb66758bd404c8681
F src/whereexpr.c e913aaa7b73ffcce66abcea5f197e2c538d48b5df78d0b7bba8ff4d73cc2e745
@ -1483,7 +1483,7 @@ F test/zerodamage.test e59a56443d6298ecf7435f618f0b27654f0c849e
F tool/GetFile.cs a15e08acb5dd7539b75ba23501581d7c2b462cb5
F tool/GetTclKit.bat 6afa640edc7810725aec61c3076ac617c4aaf0b7
F tool/Replace.cs 02c67258801c2fb5f63231e0ac0f220b4b36ba91
F tool/addopcodes.tcl 10c889c4a65ec6c5604e4a47306fa77ff57ae189
F tool/addopcodes.tcl edbd53806bf20e25af2373ad0c091be4385081c1aa1813b916bf093f94ed8380
F tool/build-all-msvc.bat c12328d06c45fec8baada5949e3d5af54bf8c887 x
F tool/build-shell.sh 950f47c6174f1eea171319438b93ba67ff5bf367
F tool/cg_anno.tcl f95b0006c52cf7f0496b506343415b6ee3cdcdd3 x
@ -1571,10 +1571,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P 6bf673767b8e5cedef1acff795cbe524fab8db2525c06424db4e038934a33936
R 8dfa3ca7454fc6936bedb04ccf47ee12
T *branch * left-join-view
T *sym-left-join-view *
T -sym-trunk *
P 1838a59c8a1c151bd6fc822b0ffef661803cf0e4704c917e74a04567b81740b9
R c4158b7e84d910d8bf443bd31845d425
U drh
Z 5ef873863ca7134987a034a627c04882
Z 30ed19e82c986c3025ce3aa1a6102ed4

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@ -1 +1 @@
1838a59c8a1c151bd6fc822b0ffef661803cf0e4704c917e74a04567b81740b9
3a5860d86fadcf924316707918bf283d26c53b1473e5e67f5cff59d18c2a7742

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@ -3889,6 +3889,17 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
break;
}
case TK_IF_NULL_ROW: {
int addrINR;
addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
sqlite3ExprCachePush(pParse);
inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
sqlite3ExprCachePop(pParse);
sqlite3VdbeJumpHere(v, addrINR);
sqlite3VdbeChangeP3(v, addrINR, inReg);
break;
}
/*
** Form A:
** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

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@ -193,6 +193,23 @@ columnlist ::= columnlist COMMA columnname carglist.
columnlist ::= columnname carglist.
columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}
// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
%ifdef SQLITE_OMIT_COMPOUND_SELECT
EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
REINDEX RENAME CTIME_KW IF
.
%wildcard ANY.
// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer. Keeping the operators together
// causes them to be assigned integer values that are close together,
@ -222,23 +239,6 @@ columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}
//
%token_class id ID|INDEXED.
// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
%ifdef SQLITE_OMIT_COMPOUND_SELECT
EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
REINDEX RENAME CTIME_KW IF
.
%wildcard ANY.
// And "ids" is an identifer-or-string.
//

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@ -3154,7 +3154,8 @@ static int multiSelectOrderBy(
typedef struct SubstContext {
Parse *pParse; /* The parsing context */
int iTable; /* Replace references to this table */
int iNewTable; /* New table number, or -1 */
int iNewTable; /* New table number */
int isLeftJoin; /* Add TK_IF_NULL_ROW opcodes on each replacement */
ExprList *pEList; /* Replacement expressions */
} SubstContext;
@ -3189,12 +3190,20 @@ static Expr *substExpr(
}else{
Expr *pNew;
Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
Expr ifNullRow;
assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
if( sqlite3ExprIsVector(pCopy) ){
sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
}else{
sqlite3 *db = pSubst->pParse->db;
if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
memset(&ifNullRow, 0, sizeof(ifNullRow));
ifNullRow.op = TK_IF_NULL_ROW;
ifNullRow.pLeft = pCopy;
ifNullRow.iTable = pSubst->iNewTable;
pCopy = &ifNullRow;
}
pNew = sqlite3ExprDup(db, pCopy, 0);
if( pNew && (pExpr->flags & EP_FromJoin) ){
pNew->iRightJoinTable = pExpr->iRightJoinTable;
@ -3288,14 +3297,8 @@ static void substSelect(
** FROM-clause subquery that is a candidate for flattening. (2b is
** due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
**
** (3) The subquery is not the right operand of a left outer join
** or (3b) the subquery is not a join and (3c) does not contain any
** result-set columns that could be non-NULL even if columns of the
** subquery table are NULL.
** to be more restrictive - disallowing subquery if it was the
** right operand of a left join. See tickets #306 and #3300. Relaxed
** to allow simple subqueries as the right operand of a left join
** on 2017-04-14.)
** (3) The subquery is not the right operand of a LEFT JOIN
** or the subquery is not itself a join.
**
** (4) The subquery is not DISTINCT.
**
@ -3307,7 +3310,7 @@ static void substSelect(
** DISTINCT.
**
** (7) The subquery has a FROM clause. TODO: For subqueries without
** A FROM clause, consider adding a FROM close with the special
** A FROM clause, consider adding a FROM clause with the special
** table sqlite_once that consists of a single row containing a
** single NULL.
**
@ -3491,15 +3494,13 @@ static int flattenSubquery(
**
** which is not at all the same thing.
**
** See also tickets #306 and #3300.
** See also tickets #306, #350, and #3300.
*/
if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
isLeftJoin = 1;
if( pSubSrc->nSrc>1 ){
return 0; /* Restriction (3b) */
return 0; /* Restriction (3) */
}
/* TBD: Deal with the case of result-set expressions that are non-NULL even
** when the RHS table of a LEFT JOIN is NULL. */
}
/* Restriction 17: If the sub-query is a compound SELECT, then it must
@ -3774,6 +3775,7 @@ static int flattenSubquery(
x.pParse = pParse;
x.iTable = iParent;
x.iNewTable = iNewParent;
x.isLeftJoin = isLeftJoin;
x.pEList = pSub->pEList;
substSelect(&x, pParent, 0);
}
@ -3883,6 +3885,7 @@ static int pushDownWhereTerms(
x.pParse = pParse;
x.iTable = iCursor;
x.iNewTable = iCursor;
x.isLeftJoin = 0;
x.pEList = pSubq->pEList;
pNew = substExpr(&x, pNew);
pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);

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@ -470,6 +470,11 @@ void sqlite3TreeViewExpr(TreeView *pView, const Expr *pExpr, u8 moreToFollow){
sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);
break;
}
case TK_IF_NULL_ROW: {
sqlite3TreeViewLine(pView, "IF-NULL-ROW %d", pExpr->iTable);
sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
break;
}
default: {
sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
break;

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@ -2429,6 +2429,23 @@ case OP_NotNull: { /* same as TK_NOTNULL, jump, in1 */
break;
}
/* Opcode: IfNullRow P1 P2 P3 * *
** Synopsis: if P1.nullRow then r[P3]=NULL, goto P2
**
** Check the cursor P1 to see if it is currently pointing at a NULL row.
** If it is, then set register P3 to NULL and jump immediately to P2.
** If P1 is not on a NULL row, then fall through without making any
** changes.
*/
case OP_IfNullRow: { /* jump */
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
if( p->apCsr[pOp->p1]->nullRow ){
sqlite3VdbeMemSetNull(aMem + pOp->p3);
goto jump_to_p2;
}
break;
}
/* Opcode: Column P1 P2 P3 P4 P5
** Synopsis: r[P3]=PX
**

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@ -4976,6 +4976,8 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
}else if( pOp->opcode==OP_Rowid ){
pOp->p1 = pLevel->iIdxCur;
pOp->opcode = OP_IdxRowid;
}else if( pOp->opcode==OP_IfNullRow ){
pOp->p1 = pLevel->iIdxCur;
}
}
}

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@ -39,6 +39,7 @@ set extras {
REGISTER
VECTOR
SELECT_COLUMN
IF_NULL_ROW
ASTERISK
SPAN
SPACE