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b2c4071299
mode see a fresh snapshot for each command in the function, rather than using the latest interactive command's snapshot. Also, suppress fresh snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE functions, instead using the snapshot taken for the most closely nested regular query. (This behavior is only sane for read-only functions, so the patch also enforces that such functions contain only SELECT commands.) As per my proposal of 6-Sep-2004; I note that I floated essentially the same proposal on 19-Jun-2002, but that discussion tailed off without any action. Since 8.0 seems like the right place to be taking possibly nontrivial backwards compatibility hits, let's get it done now.
59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* execdesc.h
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* plan and query descriptor accessor macros used by the executor
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* and related modules.
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*
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*
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* Portions Copyright (c) 1996-2004, 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/executor/execdesc.h,v 1.29 2004/09/13 20:07:52 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef EXECDESC_H
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#define EXECDESC_H
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#include "nodes/parsenodes.h"
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#include "nodes/execnodes.h"
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#include "tcop/dest.h"
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/* ----------------
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* query descriptor:
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*
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* a QueryDesc encapsulates everything that the executor
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* needs to execute the query
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* ---------------------
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*/
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typedef struct QueryDesc
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{
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/* These fields are provided by CreateQueryDesc */
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CmdType operation; /* CMD_SELECT, CMD_UPDATE, etc. */
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Query *parsetree; /* rewritten parsetree */
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Plan *plantree; /* planner's output */
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Snapshot snapshot; /* snapshot to use for query */
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Snapshot crosscheck_snapshot; /* crosscheck for RI update/delete */
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DestReceiver *dest; /* the destination for tuple output */
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ParamListInfo params; /* param values being passed in */
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bool doInstrument; /* TRUE requests runtime instrumentation */
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/* These fields are set by ExecutorStart */
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TupleDesc tupDesc; /* descriptor for result tuples */
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EState *estate; /* executor's query-wide state */
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PlanState *planstate; /* tree of per-plan-node state */
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} QueryDesc;
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/* in pquery.c */
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extern QueryDesc *CreateQueryDesc(Query *parsetree, Plan *plantree,
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Snapshot snapshot,
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Snapshot crosscheck_snapshot,
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DestReceiver *dest,
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ParamListInfo params,
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bool doInstrument);
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extern void FreeQueryDesc(QueryDesc *qdesc);
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#endif /* EXECDESC_H */
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