diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/sort/tuplesort.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c index 3ad81862f35..46eecbf942f 100644 --- a/src/backend/utils/sort/tuplesort.c +++ b/src/backend/utils/sort/tuplesort.c @@ -2637,8 +2637,16 @@ mergeruns(Tuplesortstate *state) } /* - * Use all the spare memory we have available for read buffers among the - * input tapes. + * Allocate a new 'memtuples' array, for the heap. It will hold one tuple + * from each input tape. + */ + state->memtupsize = numInputTapes; + state->memtuples = (SortTuple *) palloc(numInputTapes * sizeof(SortTuple)); + USEMEM(state, GetMemoryChunkSpace(state->memtuples)); + + /* + * Use all the remaining memory we have available for read buffers among + * the input tapes. * * We do this only after checking for the case that we produced only one * initial run, because there is no need to use a large read buffer when @@ -2661,17 +2669,9 @@ mergeruns(Tuplesortstate *state) (state->availMem) / 1024, numInputTapes); #endif - state->read_buffer_size = state->availMem / numInputTapes; + state->read_buffer_size = Min(state->availMem / numInputTapes, 0); USEMEM(state, state->availMem); - /* - * Allocate a new 'memtuples' array, for the heap. It will hold one tuple - * from each input tape. - */ - state->memtupsize = numInputTapes; - state->memtuples = (SortTuple *) palloc(numInputTapes * sizeof(SortTuple)); - USEMEM(state, GetMemoryChunkSpace(state->memtuples)); - /* End of step D2: rewind all output tapes to prepare for merging */ for (tapenum = 0; tapenum < state->tapeRange; tapenum++) LogicalTapeRewindForRead(state->tapeset, tapenum, state->read_buffer_size); |