diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index f605c1abaee..9554704456c 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -27,6 +27,7 @@ * heap_multi_insert - insert multiple tuples into a relation * heap_delete - delete a tuple from a relation * heap_update - replace a tuple in a relation with another tuple + * heap_sync - sync heap, for when no WAL has been written * * NOTES * This file contains the heap_ routines which implement @@ -2102,6 +2103,12 @@ FreeBulkInsertState(BulkInsertState bistate) * The new tuple is stamped with current transaction ID and the specified * command ID. * + * If the HEAP_INSERT_SKIP_WAL option is specified, the new tuple is not + * logged in WAL, even for a non-temp relation. Safe usage of this behavior + * requires that we arrange that all new tuples go into new pages not + * containing any tuples from other transactions, and that the relation gets + * fsync'd before commit. (See also heap_sync() comments) + * * The HEAP_INSERT_SKIP_FSM option is passed directly to * RelationGetBufferForTuple, which see for more info. * @@ -2210,7 +2217,7 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid, MarkBufferDirty(buffer); /* XLOG stuff */ - if (RelationNeedsWAL(relation)) + if (!(options & HEAP_INSERT_SKIP_WAL) && RelationNeedsWAL(relation)) { xl_heap_insert xlrec; xl_heap_header xlhdr; @@ -2418,7 +2425,7 @@ heap_multi_insert(Relation relation, HeapTuple *tuples, int ntuples, /* currently not needed (thus unsupported) for heap_multi_insert() */ AssertArg(!(options & HEAP_INSERT_NO_LOGICAL)); - needwal = RelationNeedsWAL(relation); + needwal = !(options & HEAP_INSERT_SKIP_WAL) && RelationNeedsWAL(relation); saveFreeSpace = RelationGetTargetPageFreeSpace(relation, HEAP_DEFAULT_FILLFACTOR); @@ -8746,13 +8753,18 @@ heap2_redo(XLogReaderState *record) } /* - * heap_sync - for binary compatibility - * - * A newer PostgreSQL version removes this function. It exists here just in - * case an extension calls it. See "Skipping WAL for New RelFileNode" in - * src/backend/access/transam/README for the system that superseded it, - * allowing removal of most calls. Cases like copy_relation_data() should - * call smgrimmedsync() directly. + * heap_sync - sync a heap, for use when no WAL has been written + * + * This forces the heap contents (including TOAST heap if any) down to disk. + * If we skipped using WAL, and WAL is otherwise needed, we must force the + * relation down to disk before it's safe to commit the transaction. This + * requires writing out any dirty buffers and then doing a forced fsync. + * + * Indexes are not touched. (Currently, index operations associated with + * the commands that use this are WAL-logged and so do not need fsync. + * That behavior might change someday, but in any case it's likely that + * any fsync decisions required would be per-index and hence not appropriate + * to be done here.) */ void heap_sync(Relation rel) |