diff options
Diffstat (limited to 'src/backend/access/heap/hio.c')
| -rw-r--r-- | src/backend/access/heap/hio.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c index c275b08494d..21f808fecb5 100644 --- a/src/backend/access/heap/hio.c +++ b/src/backend/access/heap/hio.c @@ -283,6 +283,24 @@ RelationAddBlocks(Relation relation, BulkInsertState bistate, */ extend_by_pages += extend_by_pages * waitcount; + /* --- + * If we previously extended using the same bistate, it's very likely + * we'll extend some more. Try to extend by as many pages as + * before. This can be important for performance for several reasons, + * including: + * + * - It prevents mdzeroextend() switching between extending the + * relation in different ways, which is inefficient for some + * filesystems. + * + * - Contention is often intermittent. Even if we currently don't see + * other waiters (see above), extending by larger amounts can + * prevent future contention. + * --- + */ + if (bistate) + extend_by_pages = Max(extend_by_pages, bistate->already_extended_by); + /* * Can't extend by more than MAX_BUFFERS_TO_EXTEND_BY, we need to pin * them all concurrently. @@ -409,6 +427,7 @@ RelationAddBlocks(Relation relation, BulkInsertState bistate, /* maintain bistate->current_buf */ IncrBufferRefCount(buffer); bistate->current_buf = buffer; + bistate->already_extended_by += extend_by_pages; } return buffer; |