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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2013-08-30 19:15:21 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2013-08-30 19:15:21 -0400 |
| commit | 8e2b71d2d0381f7acc820a2400580a1e3a6add8c (patch) | |
| tree | 2e419f5090c23820a43397c391627150bf7fae41 /src | |
| parent | 9381cb5229da1f3556909585b38ada347d798161 (diff) | |
| download | postgresql-8e2b71d2d0381f7acc820a2400580a1e3a6add8c.tar.gz postgresql-8e2b71d2d0381f7acc820a2400580a1e3a6add8c.zip | |
Reset the binary heap in MergeAppend rescans.
Failing to do so can cause queries to return wrong data, error out or crash.
This requires adding a new binaryheap_reset() method to binaryheap.c,
but that probably should have been there anyway.
Per bug #8410 from Terje Elde. Diagnosis and patch by Andres Freund.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/executor/nodeMergeAppend.c | 1 | ||||
| -rw-r--r-- | src/backend/lib/binaryheap.c | 20 | ||||
| -rw-r--r-- | src/include/lib/binaryheap.h | 1 |
3 files changed, 19 insertions, 3 deletions
diff --git a/src/backend/executor/nodeMergeAppend.c b/src/backend/executor/nodeMergeAppend.c index 5a48f7ab13b..c3edd618591 100644 --- a/src/backend/executor/nodeMergeAppend.c +++ b/src/backend/executor/nodeMergeAppend.c @@ -297,5 +297,6 @@ ExecReScanMergeAppend(MergeAppendState *node) if (subnode->chgParam == NULL) ExecReScan(subnode); } + binaryheap_reset(node->ms_heap); node->ms_initialized = false; } diff --git a/src/backend/lib/binaryheap.c b/src/backend/lib/binaryheap.c index 4b4fc945c32..7125970a50f 100644 --- a/src/backend/lib/binaryheap.c +++ b/src/backend/lib/binaryheap.c @@ -36,17 +36,31 @@ binaryheap_allocate(int capacity, binaryheap_comparator compare, void *arg) binaryheap *heap; sz = offsetof(binaryheap, bh_nodes) +sizeof(Datum) * capacity; - heap = palloc(sz); - heap->bh_size = 0; + heap = (binaryheap *) palloc(sz); heap->bh_space = capacity; - heap->bh_has_heap_property = true; heap->bh_compare = compare; heap->bh_arg = arg; + heap->bh_size = 0; + heap->bh_has_heap_property = true; + return heap; } /* + * binaryheap_reset + * + * Resets the heap to an empty state, losing its data content but not the + * parameters passed at allocation. + */ +void +binaryheap_reset(binaryheap *heap) +{ + heap->bh_size = 0; + heap->bh_has_heap_property = true; +} + +/* * binaryheap_free * * Releases memory used by the given binaryheap. diff --git a/src/include/lib/binaryheap.h b/src/include/lib/binaryheap.h index 1e99e72e515..85cafe4d4dd 100644 --- a/src/include/lib/binaryheap.h +++ b/src/include/lib/binaryheap.h @@ -40,6 +40,7 @@ typedef struct binaryheap extern binaryheap *binaryheap_allocate(int capacity, binaryheap_comparator compare, void *arg); +extern void binaryheap_reset(binaryheap *heap); extern void binaryheap_free(binaryheap *heap); extern void binaryheap_add_unordered(binaryheap *heap, Datum d); extern void binaryheap_build(binaryheap *heap); |