diff options
Diffstat (limited to 'src/backend/executor/nodeAgg.c')
| -rw-r--r-- | src/backend/executor/nodeAgg.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index 5b4a6029529..6b8ef40599b 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -1312,9 +1312,14 @@ build_hash_table(AggState *aggstate) * by themselves, and secondly ctids for row-marks. * * To eliminate duplicates, we build a bitmapset of the needed columns, and - * then build an array of the columns included in the hashtable. Note that - * the array is preserved over ExecReScanAgg, so we allocate it in the - * per-query context (unlike the hash table itself). + * then build an array of the columns included in the hashtable. We might + * still have duplicates if the passed-in grpColIdx has them, which can happen + * in edge cases from semijoins/distinct; these can't always be removed, + * because it's not certain that the duplicate cols will be using the same + * hash function. + * + * Note that the array is preserved over ExecReScanAgg, so we allocate it in + * the per-query context (unlike the hash table itself). */ static void find_hash_columns(AggState *aggstate) @@ -1335,6 +1340,7 @@ find_hash_columns(AggState *aggstate) AttrNumber *grpColIdx = perhash->aggnode->grpColIdx; List *hashTlist = NIL; TupleDesc hashDesc; + int maxCols; int i; perhash->largestGrpColIdx = 0; @@ -1359,15 +1365,24 @@ find_hash_columns(AggState *aggstate) colnos = bms_del_member(colnos, attnum); } } - /* Add in all the grouping columns */ - for (i = 0; i < perhash->numCols; i++) - colnos = bms_add_member(colnos, grpColIdx[i]); + + /* + * Compute maximum number of input columns accounting for possible + * duplications in the grpColIdx array, which can happen in some edge + * cases where HashAggregate was generated as part of a semijoin or a + * DISTINCT. + */ + maxCols = bms_num_members(colnos) + perhash->numCols; perhash->hashGrpColIdxInput = - palloc(bms_num_members(colnos) * sizeof(AttrNumber)); + palloc(maxCols * sizeof(AttrNumber)); perhash->hashGrpColIdxHash = palloc(perhash->numCols * sizeof(AttrNumber)); + /* Add all the grouping columns to colnos */ + for (i = 0; i < perhash->numCols; i++) + colnos = bms_add_member(colnos, grpColIdx[i]); + /* * First build mapping for columns directly hashed. These are the * first, because they'll be accessed when computing hash values and |