diff options
Diffstat (limited to 'src/backend/utils')
| -rw-r--r-- | src/backend/utils/adt/orderedsetaggs.c | 5 | ||||
| -rw-r--r-- | src/backend/utils/sort/tuplesort.c | 28 |
2 files changed, 20 insertions, 13 deletions
diff --git a/src/backend/utils/adt/orderedsetaggs.c b/src/backend/utils/adt/orderedsetaggs.c index e462fbd539..8502fcfc82 100644 --- a/src/backend/utils/adt/orderedsetaggs.c +++ b/src/backend/utils/adt/orderedsetaggs.c @@ -1190,7 +1190,7 @@ hypothetical_rank_common(FunctionCallInfo fcinfo, int flag, tuplesort_performsort(osastate->sortstate); /* iterate till we find the hypothetical row */ - while (tuplesort_gettupleslot(osastate->sortstate, true, slot, NULL)) + while (tuplesort_gettupleslot(osastate->sortstate, true, true, slot, NULL)) { bool isnull; Datum d = slot_getattr(slot, nargs + 1, &isnull); @@ -1353,7 +1353,8 @@ hypothetical_dense_rank_final(PG_FUNCTION_ARGS) slot2 = extraslot; /* iterate till we find the hypothetical row */ - while (tuplesort_gettupleslot(osastate->sortstate, true, slot, &abbrevVal)) + while (tuplesort_gettupleslot(osastate->sortstate, true, true, slot, + &abbrevVal)) { bool isnull; Datum d = slot_getattr(slot, nargs + 1, &isnull); diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c index 65cda52714..5f62cd5962 100644 --- a/src/backend/utils/sort/tuplesort.c +++ b/src/backend/utils/sort/tuplesort.c @@ -1852,7 +1852,8 @@ tuplesort_performsort(Tuplesortstate *state) * Internal routine to fetch the next tuple in either forward or back * direction into *stup. Returns FALSE if no more tuples. * Returned tuple belongs to tuplesort memory context, and must not be freed - * by caller. Caller should not use tuple following next call here. + * by caller. Note that fetched tuple is stored in memory that may be + * recycled by any future fetch. */ static bool tuplesort_gettuple_common(Tuplesortstate *state, bool forward, @@ -2101,12 +2102,15 @@ tuplesort_gettuple_common(Tuplesortstate *state, bool forward, * NULL value in leading attribute will set abbreviated value to zeroed * representation, which caller may rely on in abbreviated inequality check. * - * The slot receives a copied tuple (sometimes allocated in caller memory - * context) that will stay valid regardless of future manipulations of the - * tuplesort's state. + * If copy is true, the slot receives a copied tuple that'll that will stay + * valid regardless of future manipulations of the tuplesort's state. Memory + * is owned by the caller. If copy is false, the slot will just receive a + * pointer to a tuple held within the tuplesort, which is more efficient, but + * only safe for callers that are prepared to have any subsequent manipulation + * of the tuplesort's state invalidate slot contents. */ bool -tuplesort_gettupleslot(Tuplesortstate *state, bool forward, +tuplesort_gettupleslot(Tuplesortstate *state, bool forward, bool copy, TupleTableSlot *slot, Datum *abbrev) { MemoryContext oldcontext = MemoryContextSwitchTo(state->sortcontext); @@ -2123,8 +2127,10 @@ tuplesort_gettupleslot(Tuplesortstate *state, bool forward, if (state->sortKeys->abbrev_converter && abbrev) *abbrev = stup.datum1; - stup.tuple = heap_copy_minimal_tuple((MinimalTuple) stup.tuple); - ExecStoreMinimalTuple((MinimalTuple) stup.tuple, slot, true); + if (copy) + stup.tuple = heap_copy_minimal_tuple((MinimalTuple) stup.tuple); + + ExecStoreMinimalTuple((MinimalTuple) stup.tuple, slot, copy); return true; } else @@ -2137,8 +2143,8 @@ tuplesort_gettupleslot(Tuplesortstate *state, bool forward, /* * Fetch the next tuple in either forward or back direction. * Returns NULL if no more tuples. Returned tuple belongs to tuplesort memory - * context, and must not be freed by caller. Caller should not use tuple - * following next call here. + * context, and must not be freed by caller. Caller may not rely on tuple + * remaining valid after any further manipulation of tuplesort. */ HeapTuple tuplesort_getheaptuple(Tuplesortstate *state, bool forward) @@ -2157,8 +2163,8 @@ tuplesort_getheaptuple(Tuplesortstate *state, bool forward) /* * Fetch the next index tuple in either forward or back direction. * Returns NULL if no more tuples. Returned tuple belongs to tuplesort memory - * context, and must not be freed by caller. Caller should not use tuple - * following next call here. + * context, and must not be freed by caller. Caller may not rely on tuple + * remaining valid after any further manipulation of tuplesort. */ IndexTuple tuplesort_getindextuple(Tuplesortstate *state, bool forward) |