diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2017-10-12 15:20:04 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2017-10-12 15:20:04 -0400 |
| commit | d48bf6a94d295c3779c6af4df118d95a6606192f (patch) | |
| tree | c6e7dbfbff49c7ed20fc7dd24ee9ea8230dca57d /src/include/nodes/execnodes.h | |
| parent | 5c926e68ea61d0b795ad5438e7223e88d3e2c93f (diff) | |
Fix AggGetAggref() so it won't lie to aggregate final functions.
If we merge the transition calculations for two different aggregates,
it's reasonable to assume that the transition function should not care
which of those Aggref structs it gets from AggGetAggref(). It is not
reasonable to make the same assumption about an aggregate final function,
however. Commit 804163bc2 broke this, as it will pass whichever Aggref
was first associated with the transition state in both cases.
This doesn't create an observable bug so far as the core system is
concerned, because the only existing uses of AggGetAggref() are in
ordered-set aggregates that happen to not pay attention to anything
but the input properties of the Aggref; and besides that, we disabled
sharing of transition calculations for OSAs yesterday. Nonetheless,
if some third-party code were using AggGetAggref() in a normal aggregate,
they would be entitled to call this a bug. Hence, back-patch the fix
to 9.6 where the problem was introduced.
In passing, improve some of the comments about transition state sharing.
Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
Diffstat (limited to 'src/include/nodes/execnodes.h')
| -rw-r--r-- | src/include/nodes/execnodes.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 0f5d47ba8e4..07db76e47dc 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1795,7 +1795,7 @@ typedef struct AggState ExprContext **aggcontexts; /* econtexts for long-lived data (per GS) */ ExprContext *tmpcontext; /* econtext for input expressions */ ExprContext *curaggcontext; /* currently active aggcontext */ - AggStatePerTrans curpertrans; /* currently active trans state */ + AggStatePerTrans curpertrans; /* currently active trans state, if any */ bool input_done; /* indicates end of input */ bool agg_done; /* indicates completion of Agg scan */ int projected_set; /* The last projected grouping set */ @@ -1820,6 +1820,7 @@ typedef struct AggState TupleTableSlot *evalslot; /* slot for agg inputs */ ProjectionInfo *evalproj; /* projection machinery */ TupleDesc evaldesc; /* descriptor of input tuples */ + AggStatePerAgg curperagg; /* currently active aggregate, if any */ } AggState; /* ---------------- |