79 lines
1.8 KiB
C
79 lines
1.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* discard.c
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* The implementation of the DISCARD command
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*
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* Copyright (c) 1996-2024, PostgreSQL Global Development Group
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*
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*
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* IDENTIFICATION
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* src/backend/commands/discard.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/xact.h"
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#include "catalog/namespace.h"
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#include "commands/async.h"
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#include "commands/discard.h"
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#include "commands/prepare.h"
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#include "commands/sequence.h"
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#include "utils/guc.h"
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#include "utils/portal.h"
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static void DiscardAll(bool isTopLevel);
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/*
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* DISCARD { ALL | SEQUENCES | TEMP | PLANS }
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*/
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void
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DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
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{
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switch (stmt->target)
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{
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case DISCARD_ALL:
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DiscardAll(isTopLevel);
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break;
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case DISCARD_PLANS:
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ResetPlanCache();
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break;
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case DISCARD_SEQUENCES:
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ResetSequenceCaches();
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break;
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case DISCARD_TEMP:
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ResetTempTableNamespace();
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break;
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default:
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elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
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}
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}
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static void
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DiscardAll(bool isTopLevel)
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{
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/*
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* Disallow DISCARD ALL in a transaction block. This is arguably
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* inconsistent (we don't make a similar check in the command sequence
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* that DISCARD ALL is equivalent to), but the idea is to catch mistakes:
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* DISCARD ALL inside a transaction block would leave the transaction
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* still uncommitted.
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*/
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PreventInTransactionBlock(isTopLevel, "DISCARD ALL");
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/* Closing portals might run user-defined code, so do that first. */
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PortalHashTableDeleteAll();
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SetPGVariable("session_authorization", NIL, false);
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ResetAllOptions();
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DropAllPreparedStatements();
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Async_UnlistenAll();
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LockReleaseAll(USER_LOCKMETHOD, true);
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ResetPlanCache();
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ResetTempTableNamespace();
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ResetSequenceCaches();
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}
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