diff options
Diffstat (limited to 'src/backend/utils/sort/tuplesortvariants.c')
| -rw-r--r-- | src/backend/utils/sort/tuplesortvariants.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/src/backend/utils/sort/tuplesortvariants.c b/src/backend/utils/sort/tuplesortvariants.c index afa5bdbf042..f5d72b4752e 100644 --- a/src/backend/utils/sort/tuplesortvariants.c +++ b/src/backend/utils/sort/tuplesortvariants.c @@ -848,9 +848,19 @@ tuplesort_getindextuple(Tuplesortstate *state, bool forward) * determination of "non-equal tuple" based on simple binary inequality. A * NULL value will have a zeroed abbreviated value representation, which caller * may rely on in abbreviated inequality check. + * + * For byref Datums, if copy is true, *val is set to a copy of the Datum + * copied into the caller's memory context, so that it will stay valid + * regardless of future manipulations of the tuplesort's state (up to and + * including deleting the tuplesort). If copy is false, *val will just be + * set to a pointer to the Datum 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. + * For byval Datums, the value of the 'copy' parameter has no effect. + */ bool -tuplesort_getdatum(Tuplesortstate *state, bool forward, +tuplesort_getdatum(Tuplesortstate *state, bool forward, bool copy, Datum *val, bool *isNull, Datum *abbrev) { TuplesortPublic *base = TuplesortstateGetPublic(state); @@ -879,7 +889,11 @@ tuplesort_getdatum(Tuplesortstate *state, bool forward, else { /* use stup.tuple because stup.datum1 may be an abbreviation */ - *val = datumCopy(PointerGetDatum(stup.tuple), false, arg->datumTypeLen); + if (copy) + *val = datumCopy(PointerGetDatum(stup.tuple), false, + arg->datumTypeLen); + else + *val = PointerGetDatum(stup.tuple); *isNull = false; } |