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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2017-10-06 14:28:42 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2017-10-06 14:28:42 -0400 |
| commit | a1c2c430d33e0945da234b025b78bd265c8bdfb5 (patch) | |
| tree | 58551341e368115efa072e8b7eee155828372e92 | |
| parent | 6b87416c9a4dd305b76e619ecac36e2b968462f8 (diff) | |
| download | postgresql-a1c2c430d33e0945da234b025b78bd265c8bdfb5.tar.gz postgresql-a1c2c430d33e0945da234b025b78bd265c8bdfb5.zip | |
Fix intra-query memory leakage in nodeProjectSet.c.
Both ExecMakeFunctionResultSet() and evaluation of simple expressions
need to be done in the per-tuple memory context, not per-query, else
we leak data until end of query. This is a consideration that was
missed while refactoring code in the ProjectSet patch (note that in
pre-v10, ExecMakeFunctionResult is called in the per-tuple context).
Per bug #14843 from Ben M. Diagnosed independently by Andres and myself.
Discussion: https://postgr.es/m/20171005230321.28561.15927@wrigleys.postgresql.org
| -rw-r--r-- | src/backend/executor/execSRF.c | 2 | ||||
| -rw-r--r-- | src/backend/executor/nodeProjectSet.c | 6 |
2 files changed, 8 insertions, 0 deletions
diff --git a/src/backend/executor/execSRF.c b/src/backend/executor/execSRF.c index 8bc90a6c7e8..1be683db83d 100644 --- a/src/backend/executor/execSRF.c +++ b/src/backend/executor/execSRF.c @@ -467,6 +467,8 @@ ExecInitFunctionResultSet(Expr *expr, * function itself. The argument expressions may not contain set-returning * functions (the planner is supposed to have separated evaluation for those). * + * This should be called in a short-lived (per-tuple) context. + * * This is used by nodeProjectSet.c. */ Datum diff --git a/src/backend/executor/nodeProjectSet.c b/src/backend/executor/nodeProjectSet.c index d93462c5421..68981296f90 100644 --- a/src/backend/executor/nodeProjectSet.c +++ b/src/backend/executor/nodeProjectSet.c @@ -124,12 +124,16 @@ ExecProjectSRF(ProjectSetState *node, bool continuing) { TupleTableSlot *resultSlot = node->ps.ps_ResultTupleSlot; ExprContext *econtext = node->ps.ps_ExprContext; + MemoryContext oldcontext; bool hassrf PG_USED_FOR_ASSERTS_ONLY; bool hasresult; int argno; ExecClearTuple(resultSlot); + /* Call SRFs, as well as plain expressions, in per-tuple context */ + oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory); + /* * Assume no further tuples are produced unless an ExprMultipleResult is * encountered from a set returning function. @@ -176,6 +180,8 @@ ExecProjectSRF(ProjectSetState *node, bool continuing) } } + MemoryContextSwitchTo(oldcontext); + /* ProjectSet should not be used if there's no SRFs */ Assert(hassrf); |