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https://github.com/postgres/postgres.git
synced 2025-07-18 17:42:25 +03:00
Modify processing of DECLARE CURSOR and EXPLAIN so that they can resolve the
types of unspecified parameters when submitted via extended query protocol. This worked in 8.2 but I had broken it during plancache changes. DECLARE CURSOR is now treated almost exactly like a plain SELECT through parse analysis, rewrite, and planning; only just before sending to the executor do we divert it away to ProcessUtility. This requires a special-case check in a number of places, but practically all of them were already special-casing SELECT INTO, so it's not too ugly. (Maybe it would be a good idea to merge the two by treating IntoClause as a form of utility statement? Not going to worry about that now, though.) That approach doesn't work for EXPLAIN, however, so for that I punted and used a klugy solution of running parse analysis an extra time if under extended query protocol.
This commit is contained in:
Tom Lane
@ -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/commands/copy.c,v 1.282 2007/04/18 02:28:22 momjian Exp $
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* $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.283 2007/04/27 22:05:46 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -1015,9 +1015,10 @@ DoCopy(const CopyStmt *stmt, const char *queryString)
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query = (Query *) linitial(rewritten);
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Assert(query->commandType == CMD_SELECT);
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Assert(query->utilityStmt == NULL);
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/* Query mustn't use INTO, either */
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if (query->into)
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if (query->intoClause)
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ereport(ERROR,
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("COPY (SELECT INTO) is not supported")));
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1994-5, Regents of the University of California
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.161 2007/04/16 01:14:55 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.162 2007/04/27 22:05:47 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -42,8 +42,8 @@ typedef struct ExplainState
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List *rtable; /* range table */
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} ExplainState;
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static void ExplainOneQuery(Query *query, int cursorOptions,
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ExplainStmt *stmt, const char *queryString,
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static void ExplainOneQuery(Query *query, ExplainStmt *stmt,
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const char *queryString,
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ParamListInfo params, TupOutputState *tstate);
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static double elapsed_time(instr_time *starttime);
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static void explain_outNode(StringInfo str,
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@ -102,8 +102,8 @@ ExplainQuery(ExplainStmt *stmt, const char *queryString,
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/* Explain every plan */
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foreach(l, rewritten)
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{
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ExplainOneQuery((Query *) lfirst(l), 0,
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stmt, queryString, params, tstate);
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ExplainOneQuery((Query *) lfirst(l), stmt,
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queryString, params, tstate);
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/* put a blank line between plans */
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if (lnext(l) != NULL)
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do_text_output_oneline(tstate, "");
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@ -134,8 +134,7 @@ ExplainResultDesc(ExplainStmt *stmt)
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* print out the execution plan for one Query
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*/
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static void
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ExplainOneQuery(Query *query, int cursorOptions,
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ExplainStmt *stmt, const char *queryString,
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ExplainOneQuery(Query *query, ExplainStmt *stmt, const char *queryString,
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ParamListInfo params, TupOutputState *tstate)
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{
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PlannedStmt *plan;
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@ -150,7 +149,7 @@ ExplainOneQuery(Query *query, int cursorOptions,
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}
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/* plan the query */
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plan = planner(query, cursorOptions, params);
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plan = planner(query, 0, params);
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/*
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* Update snapshot command ID to ensure this query sees results of any
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@ -187,52 +186,7 @@ ExplainOneUtility(Node *utilityStmt, ExplainStmt *stmt,
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if (utilityStmt == NULL)
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return;
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if (IsA(utilityStmt, DeclareCursorStmt))
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{
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DeclareCursorStmt *dcstmt = (DeclareCursorStmt *) utilityStmt;
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Oid *param_types;
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int num_params;
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Query *query;
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List *rewritten;
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ExplainStmt newstmt;
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/* Convert parameter type data to the form parser wants */
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getParamListTypes(params, ¶m_types, &num_params);
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/*
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* Run parse analysis and rewrite. Note this also acquires sufficient
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* locks on the source table(s).
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*
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* Because the parser and planner tend to scribble on their input, we
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* make a preliminary copy of the source querytree. This prevents
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* problems in the case that the DECLARE CURSOR is in a portal or
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* plpgsql function and is executed repeatedly. (See also the same
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* hack in COPY and PREPARE.) XXX FIXME someday.
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*/
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rewritten = pg_analyze_and_rewrite((Node *) copyObject(dcstmt->query),
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queryString,
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param_types, num_params);
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/* We don't expect more or less than one result query */
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if (list_length(rewritten) != 1 || !IsA(linitial(rewritten), Query))
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elog(ERROR, "unexpected rewrite result");
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query = (Query *) linitial(rewritten);
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if (query->commandType != CMD_SELECT)
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elog(ERROR, "unexpected rewrite result");
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/* But we must explicitly disallow DECLARE CURSOR ... SELECT INTO */
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if (query->into)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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errmsg("DECLARE CURSOR cannot specify INTO")));
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/* do not actually execute the underlying query! */
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memcpy(&newstmt, stmt, sizeof(ExplainStmt));
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newstmt.analyze = false;
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ExplainOneQuery(query, dcstmt->options, &newstmt,
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queryString, params, tstate);
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}
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else if (IsA(utilityStmt, ExecuteStmt))
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if (IsA(utilityStmt, ExecuteStmt))
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ExplainExecuteQuery((ExecuteStmt *) utilityStmt, stmt,
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queryString, params, tstate);
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else if (IsA(utilityStmt, NotifyStmt))
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@ -247,6 +201,11 @@ ExplainOneUtility(Node *utilityStmt, ExplainStmt *stmt,
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* given a planned query, execute it if needed, and then print
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* EXPLAIN output
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*
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* Since we ignore any DeclareCursorStmt that might be attached to the query,
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* if you say EXPLAIN ANALYZE DECLARE CURSOR then we'll actually run the
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* query. This is different from pre-8.3 behavior but seems more useful than
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* not running the query. No cursor will be created, however.
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*
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* This is exported because it's called back from prepare.c in the
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* EXPLAIN EXECUTE case
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*
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@ -14,7 +14,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.64 2007/04/16 01:14:55 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.65 2007/04/27 22:05:47 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -26,34 +26,34 @@
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#include "access/xact.h"
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#include "commands/portalcmds.h"
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#include "executor/executor.h"
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#include "optimizer/planner.h"
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#include "rewrite/rewriteHandler.h"
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#include "tcop/pquery.h"
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#include "tcop/tcopprot.h"
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#include "utils/memutils.h"
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/*
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* PerformCursorOpen
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* Execute SQL DECLARE CURSOR command.
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*
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* The query has already been through parse analysis, rewriting, and planning.
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* When it gets here, it looks like a SELECT PlannedStmt, except that the
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* utilityStmt field is set.
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*/
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void
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PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params,
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PerformCursorOpen(PlannedStmt *stmt, ParamListInfo params,
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const char *queryString, bool isTopLevel)
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{
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Oid *param_types;
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int num_params;
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List *rewritten;
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Query *query;
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PlannedStmt *plan;
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DeclareCursorStmt *cstmt = (DeclareCursorStmt *) stmt->utilityStmt;
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Portal portal;
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MemoryContext oldContext;
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if (cstmt == NULL || !IsA(cstmt, DeclareCursorStmt))
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elog(ERROR, "PerformCursorOpen called for non-cursor query");
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/*
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* Disallow empty-string cursor name (conflicts with protocol-level
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* unnamed portal).
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*/
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if (!stmt->portalname || stmt->portalname[0] == '\0')
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if (!cstmt->portalname || cstmt->portalname[0] == '\0')
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_NAME),
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errmsg("invalid cursor name: must not be empty")));
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@ -63,70 +63,24 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params,
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* been executed inside a transaction block (or else, it would have no
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* user-visible effect).
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*/
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if (!(stmt->options & CURSOR_OPT_HOLD))
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if (!(cstmt->options & CURSOR_OPT_HOLD))
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RequireTransactionChain(isTopLevel, "DECLARE CURSOR");
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/*
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* Don't allow both SCROLL and NO SCROLL to be specified
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*/
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if ((stmt->options & CURSOR_OPT_SCROLL) &&
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(stmt->options & CURSOR_OPT_NO_SCROLL))
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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errmsg("cannot specify both SCROLL and NO SCROLL")));
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/* Convert parameter type data to the form parser wants */
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getParamListTypes(params, ¶m_types, &num_params);
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/*
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* Run parse analysis and rewrite. Note this also acquires sufficient
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* locks on the source table(s).
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*
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* Because the parser and planner tend to scribble on their input, we
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* make a preliminary copy of the source querytree. This prevents
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* problems in the case that the DECLARE CURSOR is in a portal or plpgsql
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* function and is executed repeatedly. (See also the same hack in
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* COPY and PREPARE.) XXX FIXME someday.
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*/
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rewritten = pg_analyze_and_rewrite((Node *) copyObject(stmt->query),
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queryString, param_types, num_params);
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/* We don't expect more or less than one result query */
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if (list_length(rewritten) != 1 || !IsA(linitial(rewritten), Query))
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elog(ERROR, "unexpected rewrite result");
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query = (Query *) linitial(rewritten);
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if (query->commandType != CMD_SELECT)
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elog(ERROR, "unexpected rewrite result");
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/* But we must explicitly disallow DECLARE CURSOR ... SELECT INTO */
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if (query->into)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
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errmsg("DECLARE CURSOR cannot specify INTO")));
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if (query->rowMarks != NIL)
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ereport(ERROR,
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("DECLARE CURSOR ... FOR UPDATE/SHARE is not supported"),
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errdetail("Cursors must be READ ONLY.")));
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/* plan the query */
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plan = planner(query, stmt->options, params);
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/*
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* Create a portal and copy the plan into its memory context.
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*/
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portal = CreatePortal(stmt->portalname, false, false);
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portal = CreatePortal(cstmt->portalname, false, false);
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oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
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plan = copyObject(plan);
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stmt = copyObject(stmt);
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stmt->utilityStmt = NULL; /* make it look like plain SELECT */
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PortalDefineQuery(portal,
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NULL,
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queryString,
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"SELECT", /* cursor's query is always a SELECT */
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list_make1(plan),
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list_make1(stmt),
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NULL);
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/*----------
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@ -150,10 +104,10 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params,
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* based on whether it would require any additional runtime overhead to do
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* so.
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*/
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portal->cursorOptions = stmt->options;
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portal->cursorOptions = cstmt->options;
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if (!(portal->cursorOptions & (CURSOR_OPT_SCROLL | CURSOR_OPT_NO_SCROLL)))
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{
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if (ExecSupportsBackwardScan(plan->planTree))
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if (ExecSupportsBackwardScan(stmt->planTree))
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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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@ -10,7 +10,7 @@
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* Copyright (c) 2002-2007, 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 1.74 2007/04/26 23:24:44 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.75 2007/04/27 22:05:47 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -57,7 +57,6 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
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int nargs;
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List *queries;
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Query *query;
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const char *commandTag;
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List *query_list,
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*plan_list;
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int i;
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@ -137,22 +136,15 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
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switch (query->commandType)
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{
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case CMD_SELECT:
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commandTag = "SELECT";
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break;
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case CMD_INSERT:
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commandTag = "INSERT";
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break;
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case CMD_UPDATE:
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commandTag = "UPDATE";
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break;
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case CMD_DELETE:
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commandTag = "DELETE";
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/* OK */
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break;
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default:
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_PSTATEMENT_DEFINITION),
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errmsg("utility statements cannot be prepared")));
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commandTag = NULL; /* keep compiler quiet */
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break;
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}
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@ -168,7 +160,7 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
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StorePreparedStatement(stmt->name,
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stmt->query,
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queryString,
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commandTag,
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CreateCommandTag((Node *) query),
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argtypes,
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nargs,
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0, /* default cursor options */
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@ -244,11 +236,12 @@ ExecuteQuery(ExecuteStmt *stmt, const char *queryString,
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errmsg("prepared statement is not a SELECT")));
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pstmt = (PlannedStmt *) linitial(plan_list);
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if (!IsA(pstmt, PlannedStmt) ||
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pstmt->commandType != CMD_SELECT)
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pstmt->commandType != CMD_SELECT ||
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pstmt->utilityStmt != NULL)
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ereport(ERROR,
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(errcode(ERRCODE_WRONG_OBJECT_TYPE),
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errmsg("prepared statement is not a SELECT")));
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pstmt->into = copyObject(stmt->into);
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pstmt->intoClause = copyObject(stmt->into);
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MemoryContextSwitchTo(oldContext);
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@ -689,7 +682,8 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, ExplainStmt *stmt,
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if (execstmt->into)
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{
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if (pstmt->commandType != CMD_SELECT)
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if (pstmt->commandType != CMD_SELECT ||
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pstmt->utilityStmt != NULL)
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ereport(ERROR,
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(errcode(ERRCODE_WRONG_OBJECT_TYPE),
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errmsg("prepared statement is not a SELECT")));
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@ -697,7 +691,7 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, ExplainStmt *stmt,
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/* Copy the stmt so we can modify it */
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pstmt = copyObject(pstmt);
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pstmt->into = execstmt->into;
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pstmt->intoClause = execstmt->into;
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}
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/*
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Reference in New Issue
Block a user