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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2004-09-13 20:10:13 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2004-09-13 20:10:13 +0000 |
| commit | b2c4071299e02ed96d48d3c8e776de2fab36f88c (patch) | |
| tree | ff0db14826870f1c3fe46d94ea3a1e1697c658a7 /src/include/executor/execdesc.h | |
| parent | d69528881ab72eac5a9f154f23dbf549789c264d (diff) | |
| download | postgresql-b2c4071299e02ed96d48d3c8e776de2fab36f88c.tar.gz postgresql-b2c4071299e02ed96d48d3c8e776de2fab36f88c.zip | |
Redesign query-snapshot timing so that volatile functions in READ COMMITTED
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.
Diffstat (limited to 'src/include/executor/execdesc.h')
| -rw-r--r-- | src/include/executor/execdesc.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h index 131fa727098..c22266a4c41 100644 --- a/src/include/executor/execdesc.h +++ b/src/include/executor/execdesc.h @@ -8,7 +8,7 @@ * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/executor/execdesc.h,v 1.28 2004/08/29 04:13:06 momjian Exp $ + * $PostgreSQL: pgsql/src/include/executor/execdesc.h,v 1.29 2004/09/13 20:07:52 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -33,6 +33,8 @@ typedef struct QueryDesc CmdType operation; /* CMD_SELECT, CMD_UPDATE, etc. */ Query *parsetree; /* rewritten parsetree */ Plan *plantree; /* planner's output */ + Snapshot snapshot; /* snapshot to use for query */ + Snapshot crosscheck_snapshot; /* crosscheck for RI update/delete */ DestReceiver *dest; /* the destination for tuple output */ ParamListInfo params; /* param values being passed in */ bool doInstrument; /* TRUE requests runtime instrumentation */ @@ -45,6 +47,8 @@ typedef struct QueryDesc /* in pquery.c */ extern QueryDesc *CreateQueryDesc(Query *parsetree, Plan *plantree, + Snapshot snapshot, + Snapshot crosscheck_snapshot, DestReceiver *dest, ParamListInfo params, bool doInstrument); |