diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/executor/nodeWindowAgg.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c index 729c376d86b..692d2eee1f1 100644 --- a/src/backend/executor/nodeWindowAgg.c +++ b/src/backend/executor/nodeWindowAgg.c @@ -2648,16 +2648,24 @@ initialize_peragg(WindowAggState *winstate, WindowFunc *wfunc, * aggregate's arguments (and FILTER clause if any) contain any calls to * volatile functions. Otherwise, the difference between restarting and * not restarting the aggregation would be user-visible. + * + * We also don't risk using moving aggregates when there are subplans in + * the arguments or FILTER clause. This is partly because + * contain_volatile_functions() doesn't look inside subplans; but there + * are other reasons why a subplan's output might be volatile. For + * example, syncscan mode can render the results nonrepeatable. */ if (!OidIsValid(aggform->aggminvtransfn)) use_ma_code = false; /* sine qua non */ else if (aggform->aggmfinalmodify == AGGMODIFY_READ_ONLY && - aggform->aggfinalmodify != AGGMODIFY_READ_ONLY) + aggform->aggfinalmodify != AGGMODIFY_READ_ONLY) use_ma_code = true; /* decision forced by safety */ else if (winstate->frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING) use_ma_code = false; /* non-moving frame head */ else if (contain_volatile_functions((Node *) wfunc)) use_ma_code = false; /* avoid possible behavioral change */ + else if (contain_subplans((Node *) wfunc)) + use_ma_code = false; /* subplans might contain volatile functions */ else use_ma_code = true; /* yes, let's use it */ if (use_ma_code) |