diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 16 |
1 files changed, 3 insertions, 13 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 5a32e62ed0e..29694b8aa4a 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -7003,7 +7003,6 @@ heap_compute_xid_horizon_for_tuples(Relation rel, Page hpage; #ifdef USE_PREFETCH XidHorizonPrefetchState prefetch_state; - int io_concurrency; int prefetch_distance; #endif @@ -7026,24 +7025,15 @@ heap_compute_xid_horizon_for_tuples(Relation rel, /* * Compute the prefetch distance that we will attempt to maintain. * - * We don't use the regular formula to determine how much to prefetch - * here, but instead just add a constant to effective_io_concurrency. - * That's because it seems best to do some prefetching here even when - * effective_io_concurrency is set to 0, but if the DBA thinks it's OK to - * do more prefetching for other operations, then it's probably OK to do - * more prefetching in this case, too. It may be that this formula is too - * simplistic, but at the moment there is no evidence of that or any idea - * about what would work better. - * * Since the caller holds a buffer lock somewhere in rel, we'd better make * sure that isn't a catalog relation before we call code that does * syscache lookups, to avoid risk of deadlock. */ if (IsCatalogRelation(rel)) - io_concurrency = effective_io_concurrency; + prefetch_distance = maintenance_io_concurrency; else - io_concurrency = get_tablespace_io_concurrency(rel->rd_rel->reltablespace); - prefetch_distance = Min((io_concurrency) + 10, MAX_IO_CONCURRENCY); + prefetch_distance = + get_tablespace_maintenance_io_concurrency(rel->rd_rel->reltablespace); /* Start prefetching. */ xid_horizon_prefetch_buffer(rel, &prefetch_state, prefetch_distance); |