diff options
Diffstat (limited to 'src/backend/executor/nodeAgg.c')
| -rw-r--r-- | src/backend/executor/nodeAgg.c | 26 |
1 files changed, 11 insertions, 15 deletions
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index a6b1f194ae4..4548fe9a17d 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -55,13 +55,15 @@ * in either case its value need not be preserved. See int8inc() for an * example. Notice that advance_transition_function() is coded to avoid a * data copy step when the previous transition value pointer is returned. + * Also, some transition functions make use of the aggcontext to store + * working state. * * * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.167 2009/06/17 16:05:34 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.168 2009/07/23 20:45:27 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -273,18 +275,6 @@ initialize_aggregates(AggState *aggstate, } /* - * If we are reinitializing after a group boundary, we have to free - * any prior transValue to avoid memory leakage. We must check not - * only the isnull flag but whether the pointer is NULL; since - * pergroupstate is initialized with palloc0, the initial condition - * has isnull = 0 and null pointer. - */ - if (!peraggstate->transtypeByVal && - !pergroupstate->transValueIsNull && - DatumGetPointer(pergroupstate->transValue) != NULL) - pfree(DatumGetPointer(pergroupstate->transValue)); - - /* * (Re)set transValue to the initial value. * * Note that when the initial value is pass-by-ref, we must copy it @@ -911,10 +901,15 @@ agg_retrieve_direct(AggState *aggstate) } /* - * Clear the per-output-tuple context for each group + * Clear the per-output-tuple context for each group, as well as + * aggcontext (which contains any pass-by-ref transvalues of the + * old group). We also clear any child contexts of the aggcontext; + * some aggregate functions store working state in such contexts. */ ResetExprContext(econtext); + MemoryContextResetAndDeleteChildren(aggstate->aggcontext); + /* * Initialize working state for a new input tuple group */ @@ -1234,7 +1229,8 @@ ExecInitAgg(Agg *node, EState *estate, int eflags) * structures and transition values. NOTE: the details of what is stored * in aggcontext and what is stored in the regular per-query memory * context are driven by a simple decision: we want to reset the - * aggcontext in ExecReScanAgg to recover no-longer-wanted space. + * aggcontext at group boundaries (if not hashing) and in ExecReScanAgg + * to recover no-longer-wanted space. */ aggstate->aggcontext = AllocSetContextCreate(CurrentMemoryContext, |