Fix oversight in initial implementation of PORTAL_ONE_RETURNING mode: we
cannot assume that there's exactly one Query in the Portal, as we can for ONE_SELECT mode, because non-SELECT queries might have extra queries added during rule rewrites. Fix things up so that we'll use ONE_RETURNING mode when a Portal contains one primary (canSetTag) query and that query has a RETURNING list. This appears to be a second showstopper reason for running the Portal to completion before we start to hand anything back --- we want to be sure that the rule-added queries get run too.
This commit is contained in:
Tom Lane
parent
3d1e01caa4
commit
65b2f93b58
@ -10,7 +10,7 @@
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* Copyright (c) 2002-2006, PostgreSQL Global Development Group
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.60 2006/08/12 02:52:04 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.61 2006/08/14 22:57:15 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -448,7 +448,7 @@ FetchPreparedStatementResultDesc(PreparedStatement *stmt)
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return ExecCleanTypeFromTL(query->targetList, false);
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case PORTAL_ONE_RETURNING:
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query = (Query *) linitial(stmt->query_list);
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query = PortalListGetPrimaryQuery(stmt->query_list);
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return ExecCleanTypeFromTL(query->returningList, false);
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case PORTAL_UTIL_SELECT:
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@ -505,7 +505,7 @@ FetchPreparedStatementTargetList(PreparedStatement *stmt)
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if (strategy == PORTAL_ONE_SELECT)
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return ((Query *) linitial(stmt->query_list))->targetList;
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if (strategy == PORTAL_ONE_RETURNING)
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return ((Query *) linitial(stmt->query_list))->returningList;
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return (PortalListGetPrimaryQuery(stmt->query_list))->returningList;
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if (strategy == PORTAL_UTIL_SELECT)
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{
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Node *utilityStmt;
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.156 2006/08/14 13:40:18 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.157 2006/08/14 22:57:15 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -818,31 +818,44 @@ SPI_cursor_open(const char *name, void *plan,
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bool read_only)
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{
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_SPI_plan *spiplan = (_SPI_plan *) plan;
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List *qtlist = spiplan->qtlist;
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List *ptlist = spiplan->ptlist;
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Query *queryTree;
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Plan *planTree;
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List *qtlist;
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List *ptlist;
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ParamListInfo paramLI;
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Snapshot snapshot;
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MemoryContext oldcontext;
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Portal portal;
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int k;
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/* Ensure that the plan contains only one query */
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if (list_length(ptlist) != 1 || list_length(qtlist) != 1)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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errmsg("cannot open multi-query plan as cursor")));
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queryTree = (Query *) linitial((List *) linitial(qtlist));
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planTree = (Plan *) linitial(ptlist);
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/*
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* Check that the plan is something the Portal code will special-case
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* as returning one tupleset.
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*/
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if (!SPI_is_cursor_plan(spiplan))
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{
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/* try to give a good error message */
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Query *queryTree;
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/* Must be a query that returns tuples */
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if (!QueryReturnsTuples(queryTree))
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if (list_length(spiplan->qtlist) != 1)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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errmsg("cannot open multi-query plan as cursor")));
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queryTree = PortalListGetPrimaryQuery((List *) linitial(spiplan->qtlist));
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if (queryTree == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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errmsg("cannot open empty query as cursor")));
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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/* translator: %s is name of a SQL command, eg INSERT */
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errmsg("cannot open %s query as cursor",
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CreateQueryTag(queryTree))));
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}
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Assert(list_length(spiplan->qtlist) == 1);
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qtlist = (List *) linitial(spiplan->qtlist);
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ptlist = spiplan->ptlist;
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if (list_length(qtlist) != list_length(ptlist))
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elog(ERROR, "corrupted SPI plan lists");
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/* Reset SPI result (note we deliberately don't touch lastoid) */
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SPI_processed = 0;
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@ -862,10 +875,10 @@ SPI_cursor_open(const char *name, void *plan,
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portal = CreatePortal(name, false, false);
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}
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/* Switch to portal's memory and copy the parsetree and plan to there */
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/* Switch to portal's memory and copy the parsetrees and plans to there */
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oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
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queryTree = copyObject(queryTree);
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planTree = copyObject(planTree);
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qtlist = copyObject(qtlist);
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ptlist = copyObject(ptlist);
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/* If the plan has parameters, set them up */
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if (spiplan->nargs > 0)
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@ -907,9 +920,9 @@ SPI_cursor_open(const char *name, void *plan,
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PortalDefineQuery(portal,
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NULL, /* no statement name */
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spiplan->query,
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CreateQueryTag(queryTree),
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list_make1(queryTree),
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list_make1(planTree),
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CreateQueryTag(PortalListGetPrimaryQuery(qtlist)),
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qtlist,
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ptlist,
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PortalGetHeapMemory(portal));
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MemoryContextSwitchTo(oldcontext);
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@ -918,7 +931,8 @@ SPI_cursor_open(const char *name, void *plan,
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* Set up options for portal.
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*/
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portal->cursorOptions &= ~(CURSOR_OPT_SCROLL | CURSOR_OPT_NO_SCROLL);
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if (planTree == NULL || ExecSupportsBackwardScan(planTree))
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if (list_length(ptlist) == 1 &&
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ExecSupportsBackwardScan((Plan *) linitial(ptlist)))
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portal->cursorOptions |= CURSOR_OPT_SCROLL;
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else
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portal->cursorOptions |= CURSOR_OPT_NO_SCROLL;
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@ -940,16 +954,7 @@ SPI_cursor_open(const char *name, void *plan,
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*/
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PortalStart(portal, paramLI, snapshot);
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/*
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* If this test fails then we're out of sync with pquery.c about
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* which queries can return tuples...
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*/
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if (portal->strategy == PORTAL_MULTI_QUERY)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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/* translator: %s is name of a SQL command, eg INSERT */
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errmsg("cannot open %s query as cursor",
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CreateQueryTag(queryTree))));
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Assert(portal->strategy != PORTAL_MULTI_QUERY);
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/* Return the created portal */
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return portal;
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@ -1050,7 +1055,6 @@ bool
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SPI_is_cursor_plan(void *plan)
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{
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_SPI_plan *spiplan = (_SPI_plan *) plan;
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List *qtlist;
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if (spiplan == NULL)
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{
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@ -1058,13 +1062,20 @@ SPI_is_cursor_plan(void *plan)
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return false;
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}
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qtlist = spiplan->qtlist;
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if (list_length(spiplan->ptlist) == 1 && list_length(qtlist) == 1)
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{
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Query *queryTree = (Query *) linitial((List *) linitial(qtlist));
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if (list_length(spiplan->qtlist) != 1)
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return false; /* not exactly 1 pre-rewrite command */
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if (QueryReturnsTuples(queryTree))
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switch (ChoosePortalStrategy((List *) linitial(spiplan->qtlist)))
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{
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case PORTAL_ONE_SELECT:
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case PORTAL_ONE_RETURNING:
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case PORTAL_UTIL_SELECT:
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/* OK */
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return true;
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case PORTAL_MULTI_QUERY:
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/* will not return tuples */
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break;
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}
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return false;
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}
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/tcop/pquery.c,v 1.106 2006/08/12 02:52:05 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/tcop/pquery.c,v 1.107 2006/08/14 22:57:15 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -213,30 +213,59 @@ ProcessQuery(Query *parsetree,
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PortalStrategy
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ChoosePortalStrategy(List *parseTrees)
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{
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PortalStrategy strategy;
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strategy = PORTAL_MULTI_QUERY; /* default assumption */
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int nSetTag;
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ListCell *lc;
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/*
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* PORTAL_ONE_SELECT and PORTAL_UTIL_SELECT need only consider the
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* single-Query-struct case, since there are no rewrite rules that
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* can add auxiliary queries to a SELECT or a utility command.
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*/
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if (list_length(parseTrees) == 1)
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{
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Query *query = (Query *) linitial(parseTrees);
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Assert(IsA(query, Query));
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if (query->canSetTag)
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{
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if (query->commandType == CMD_SELECT &&
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query->into == NULL)
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strategy = PORTAL_ONE_SELECT;
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else if (query->returningList != NIL)
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strategy = PORTAL_ONE_RETURNING;
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else if (query->commandType == CMD_UTILITY &&
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query->utilityStmt != NULL)
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return PORTAL_ONE_SELECT;
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if (query->commandType == CMD_UTILITY &&
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query->utilityStmt != NULL)
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{
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if (UtilityReturnsTuples(query->utilityStmt))
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strategy = PORTAL_UTIL_SELECT;
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return PORTAL_UTIL_SELECT;
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/* it can't be ONE_RETURNING, so give up */
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return PORTAL_MULTI_QUERY;
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}
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}
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}
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return strategy;
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/*
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* PORTAL_ONE_RETURNING has to allow auxiliary queries added by rewrite.
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* Choose PORTAL_ONE_RETURNING if there is exactly one canSetTag query
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* and it has a RETURNING list.
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*/
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nSetTag = 0;
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foreach(lc, parseTrees)
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{
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Query *query = (Query *) lfirst(lc);
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Assert(IsA(query, Query));
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if (query->canSetTag)
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{
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if (++nSetTag > 1)
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return PORTAL_MULTI_QUERY; /* no need to look further */
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if (query->returningList == NIL)
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return PORTAL_MULTI_QUERY; /* no need to look further */
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}
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}
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if (nSetTag == 1)
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return PORTAL_ONE_RETURNING;
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/* Else, it's the general case... */
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return PORTAL_MULTI_QUERY;
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}
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/*
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@ -255,7 +284,7 @@ FetchPortalTargetList(Portal portal)
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if (portal->strategy == PORTAL_ONE_SELECT)
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return ((Query *) linitial(portal->parseTrees))->targetList;
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if (portal->strategy == PORTAL_ONE_RETURNING)
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return ((Query *) linitial(portal->parseTrees))->returningList;
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return (PortalGetPrimaryQuery(portal))->returningList;
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if (portal->strategy == PORTAL_UTIL_SELECT)
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{
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Node *utilityStmt;
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@ -422,7 +451,7 @@ PortalStart(Portal portal, ParamListInfo params, Snapshot snapshot)
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* the portal. We do need to set up the result tupdesc.
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*/
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portal->tupDesc =
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ExecCleanTypeFromTL(((Query *) linitial(portal->parseTrees))->returningList, false);
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ExecCleanTypeFromTL((PortalGetPrimaryQuery(portal))->returningList, false);
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/*
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* Reset cursor position data to "start of query"
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@ -894,10 +923,11 @@ FillPortalStore(Portal portal)
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{
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case PORTAL_ONE_RETURNING:
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/*
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* We run the query just as if it were in a MULTI portal,
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* but send the output to the tuplestore.
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* Run the portal to completion just as for the default MULTI_QUERY
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* case, but send the primary query's output to the tuplestore.
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* Auxiliary query outputs are discarded.
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*/
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PortalRunMulti(portal, treceiver, treceiver, completionTag);
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PortalRunMulti(portal, treceiver, None_Receiver, completionTag);
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/* Override default completion tag with actual command result */
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portal->commandTag = pstrdup(completionTag);
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break;
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@ -12,7 +12,7 @@
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.91 2006/08/08 01:23:15 momjian Exp $
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* $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.92 2006/08/14 22:57:15 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -146,6 +146,34 @@ GetPortalByName(const char *name)
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return portal;
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}
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/*
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* PortalListGetPrimaryQuery
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* Get the "primary" Query within a portal, ie, the one marked canSetTag.
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*
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* Returns NULL if no such Query. If multiple Query structs within the
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* portal are marked canSetTag, returns the first one. Neither of these
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* cases should occur in present usages of this function.
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*
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* Note: the reason this is just handed a List is so that prepared statements
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* can share the code. For use with a portal, use PortalGetPrimaryQuery
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* rather than calling this directly.
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*/
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Query *
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PortalListGetPrimaryQuery(List *parseTrees)
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{
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ListCell *lc;
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foreach(lc, parseTrees)
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{
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Query *query = (Query *) lfirst(lc);
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Assert(IsA(query, Query));
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if (query->canSetTag)
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return query;
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}
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return NULL;
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}
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/*
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* CreatePortal
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* Returns a new portal given a name.
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@ -39,7 +39,7 @@
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* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.65 2006/08/12 02:52:06 tgl Exp $
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* $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.66 2006/08/14 22:57:15 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -63,10 +63,13 @@
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* tuplestore for access after transaction completion).
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*
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* PORTAL_ONE_RETURNING: the portal contains a single INSERT/UPDATE/DELETE
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* query with a RETURNING clause. On first execution, we run the statement
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* and dump its results into the portal tuplestore; the results are then
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* returned to the client as demanded. (We can't support suspension of
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* the query partway through, because the AFTER TRIGGER code can't cope.)
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* query with a RETURNING clause (plus possibly auxiliary queries added by
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* rule rewriting). On first execution, we run the portal to completion
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* and dump the primary query's results into the portal tuplestore; the
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* results are then returned to the client as demanded. (We can't support
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* suspension of the query partway through, because the AFTER TRIGGER code
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* can't cope, and also because we don't want to risk failing to execute
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* all the auxiliary queries.)
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*
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* PORTAL_UTIL_SELECT: the portal contains a utility statement that returns
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* a SELECT-like result (for example, EXPLAIN or SHOW). On first execution,
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@ -187,6 +190,7 @@ typedef struct PortalData
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*/
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#define PortalGetQueryDesc(portal) ((portal)->queryDesc)
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#define PortalGetHeapMemory(portal) ((portal)->heap)
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#define PortalGetPrimaryQuery(portal) PortalListGetPrimaryQuery((portal)->parseTrees)
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/* Prototypes for functions in utils/mmgr/portalmem.c */
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@ -215,6 +219,7 @@ extern void PortalDefineQuery(Portal portal,
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List *parseTrees,
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List *planTrees,
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MemoryContext queryContext);
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extern Query *PortalListGetPrimaryQuery(List *parseTrees);
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extern void PortalCreateHoldStore(Portal portal);
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#endif /* PORTAL_H */
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