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| author | Andres Freund <andres@anarazel.de> | 2019-01-15 12:19:21 -0800 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2019-01-15 12:19:21 -0800 |
| commit | 90525d7b4e0fe5ebd53960cd7ef59ee11ff06516 (patch) | |
| tree | d23008d7e6b11540e95a9b28b7daed450f0357a2 | |
| parent | 285d8e12055f27bce5675e93fef365b6c337f2b3 (diff) | |
| download | postgresql-90525d7b4e0fe5ebd53960cd7ef59ee11ff06516.tar.gz postgresql-90525d7b4e0fe5ebd53960cd7ef59ee11ff06516.zip | |
Don't duplicate parallel seqscan shmem sizing logic in nbtree.
This is architecturally mildly problematic, which becomes more
pronounced with the upcoming introduction of pluggable storage.
To fix, teach heap_parallelscan_estimate() to deal with SnapshotAny
snapshots, and then use it from _bt_parallel_estimate_shared().
Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
| -rw-r--r-- | src/backend/access/heap/heapam.c | 10 | ||||
| -rw-r--r-- | src/backend/access/nbtree/nbtsort.c | 13 |
2 files changed, 11 insertions, 12 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index f7b08ffdd13..9afbc8228de 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -1615,8 +1615,14 @@ heap_endscan(HeapScanDesc scan) Size heap_parallelscan_estimate(Snapshot snapshot) { - return add_size(offsetof(ParallelHeapScanDescData, phs_snapshot_data), - EstimateSnapshotSpace(snapshot)); + Size sz = offsetof(ParallelHeapScanDescData, phs_snapshot_data); + + if (IsMVCCSnapshot(snapshot)) + sz = add_size(sz, EstimateSnapshotSpace(snapshot)); + else + Assert(snapshot == SnapshotAny); + + return sz; } /* ---------------- diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c index 83966dc4d41..5cc3cf57e22 100644 --- a/src/backend/access/nbtree/nbtsort.c +++ b/src/backend/access/nbtree/nbtsort.c @@ -158,7 +158,7 @@ typedef struct BTShared /* * This variable-sized field must come last. * - * See _bt_parallel_estimate_shared(). + * See _bt_parallel_estimate_shared() and heap_parallelscan_estimate(). */ ParallelHeapScanDescData heapdesc; } BTShared; @@ -1405,15 +1405,8 @@ _bt_end_parallel(BTLeader *btleader) static Size _bt_parallel_estimate_shared(Snapshot snapshot) { - if (!IsMVCCSnapshot(snapshot)) - { - Assert(snapshot == SnapshotAny); - return sizeof(BTShared); - } - - return add_size(offsetof(BTShared, heapdesc) + - offsetof(ParallelHeapScanDescData, phs_snapshot_data), - EstimateSnapshotSpace(snapshot)); + return add_size(offsetof(BTShared, heapdesc), + heap_parallelscan_estimate(snapshot)); } /* |