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author | Noah Misch <noah@leadboat.com> | 2020-03-21 09:38:26 -0700 |
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committer | Noah Misch <noah@leadboat.com> | 2020-03-21 09:38:30 -0700 |
commit | e4b0a02ef8c8c69f2a49f4ca86de12ef34e97ac3 (patch) | |
tree | 02408dc63449eac2a32b14b47b162c996ece9f86 /src/include/access | |
parent | a5abec521c5d40fefbbb42af093fa9fd508b2614 (diff) | |
download | postgresql-e4b0a02ef8c8c69f2a49f4ca86de12ef34e97ac3.tar.gz postgresql-e4b0a02ef8c8c69f2a49f4ca86de12ef34e97ac3.zip |
Skip WAL for new relfilenodes, under wal_level=minimal.
Until now, only selected bulk operations (e.g. COPY) did this. If a
given relfilenode received both a WAL-skipping COPY and a WAL-logged
operation (e.g. INSERT), recovery could lose tuples from the COPY. See
src/backend/access/transam/README section "Skipping WAL for New
RelFileNode" for the new coding rules. Maintainers of table access
methods should examine that section.
To maintain data durability, just before commit, we choose between an
fsync of the relfilenode and copying its contents to WAL. A new GUC,
wal_skip_threshold, guides that choice. If this change slows a workload
that creates small, permanent relfilenodes under wal_level=minimal, try
adjusting wal_skip_threshold. Users setting a timeout on COMMIT may
need to adjust that timeout, and log_min_duration_statement analysis
will reflect time consumption moving to COMMIT from commands like COPY.
Internally, this requires a reliable determination of whether
RollbackAndReleaseCurrentSubTransaction() would unlink a relation's
current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the
specification of rd_createSubid such that the field is zero when a new
rel has an old rd_node. Make relcache.c retain entries for certain
dropped relations until end of transaction.
Back-patch to 9.5 (all supported versions). This introduces a new WAL
record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As
always, update standby systems before master systems. This changes
sizeof(RelationData) and sizeof(IndexStmt), breaking binary
compatibility for affected extensions. (The most recent commit to
affect the same class of extensions was
089e4d405d0f3b94c74a2c6a54357a84a681754b.)
Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert
Haas. Heikki Linnakangas and Michael Paquier implemented earlier
designs that materially clarified the problem. Reviewed, in earlier
designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane,
Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout.
Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
Diffstat (limited to 'src/include/access')
-rw-r--r-- | src/include/access/gist_private.h | 2 | ||||
-rw-r--r-- | src/include/access/gistxlog.h | 1 | ||||
-rw-r--r-- | src/include/access/heapam.h | 1 | ||||
-rw-r--r-- | src/include/access/rewriteheap.h | 2 | ||||
-rw-r--r-- | src/include/access/tableam.h | 15 |
5 files changed, 8 insertions, 13 deletions
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h index c491ed65fc9..e38d97358c0 100644 --- a/src/include/access/gist_private.h +++ b/src/include/access/gist_private.h @@ -448,6 +448,8 @@ extern XLogRecPtr gistXLogSplit(bool page_is_leaf, BlockNumber origrlink, GistNSN oldnsn, Buffer leftchild, bool markfollowright); +extern XLogRecPtr gistXLogAssignLSN(void); + /* gistget.c */ extern bool gistgettuple(IndexScanDesc scan, ScanDirection dir); extern int64 gistgetbitmap(IndexScanDesc scan, TIDBitmap *tbm); diff --git a/src/include/access/gistxlog.h b/src/include/access/gistxlog.h index e44922d915c..596a881e49f 100644 --- a/src/include/access/gistxlog.h +++ b/src/include/access/gistxlog.h @@ -26,6 +26,7 @@ /* #define XLOG_GIST_INSERT_COMPLETE 0x40 */ /* not used anymore */ /* #define XLOG_GIST_CREATE_INDEX 0x50 */ /* not used anymore */ #define XLOG_GIST_PAGE_DELETE 0x60 +#define XLOG_GIST_ASSIGN_LSN 0x70 /* nop, assign new LSN */ /* * Backup Blk 0: updated page. diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h index dffb57bf11a..b6ad1dd5f82 100644 --- a/src/include/access/heapam.h +++ b/src/include/access/heapam.h @@ -29,7 +29,6 @@ /* "options" flag bits for heap_insert */ -#define HEAP_INSERT_SKIP_WAL TABLE_INSERT_SKIP_WAL #define HEAP_INSERT_SKIP_FSM TABLE_INSERT_SKIP_FSM #define HEAP_INSERT_FROZEN TABLE_INSERT_FROZEN #define HEAP_INSERT_NO_LOGICAL TABLE_INSERT_NO_LOGICAL diff --git a/src/include/access/rewriteheap.h b/src/include/access/rewriteheap.h index 80562539161..7f9736e294f 100644 --- a/src/include/access/rewriteheap.h +++ b/src/include/access/rewriteheap.h @@ -23,7 +23,7 @@ typedef struct RewriteStateData *RewriteState; extern RewriteState begin_heap_rewrite(Relation OldHeap, Relation NewHeap, TransactionId OldestXmin, TransactionId FreezeXid, - MultiXactId MultiXactCutoff, bool use_wal); + MultiXactId MultiXactCutoff); extern void end_heap_rewrite(RewriteState state); extern void rewrite_heap_tuple(RewriteState state, HeapTuple oldTuple, HeapTuple newTuple); diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index 9653f80a091..a585c1893e3 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -128,7 +128,7 @@ typedef struct TM_FailureData } TM_FailureData; /* "options" flag bits for table_tuple_insert */ -#define TABLE_INSERT_SKIP_WAL 0x0001 +/* TABLE_INSERT_SKIP_WAL was 0x0001; RelationNeedsWAL() now governs */ #define TABLE_INSERT_SKIP_FSM 0x0002 #define TABLE_INSERT_FROZEN 0x0004 #define TABLE_INSERT_NO_LOGICAL 0x0008 @@ -410,9 +410,8 @@ typedef struct TableAmRoutine /* * Perform operations necessary to complete insertions made via - * tuple_insert and multi_insert with a BulkInsertState specified. This - * may for example be used to flush the relation, when the - * TABLE_INSERT_SKIP_WAL option was used. + * tuple_insert and multi_insert with a BulkInsertState specified. In-tree + * access methods ceased to use this. * * Typically callers of tuple_insert and multi_insert will just pass all * the flags that apply to them, and each AM has to decide which of them @@ -1101,10 +1100,6 @@ table_compute_xid_horizon_for_tuples(Relation rel, * The options bitmask allows the caller to specify options that may change the * behaviour of the AM. The AM will ignore options that it does not support. * - * If the TABLE_INSERT_SKIP_WAL option is specified, the new tuple doesn't - * need to be logged to WAL, even for a non-temp relation. It is the AMs - * choice whether this optimization is supported. - * * If the TABLE_INSERT_SKIP_FSM option is specified, AMs are free to not reuse * free space in the relation. This can save some cycles when we know the * relation is new and doesn't contain useful amounts of free space. @@ -1324,9 +1319,7 @@ table_tuple_lock(Relation rel, ItemPointer tid, Snapshot snapshot, /* * Perform operations necessary to complete insertions made via - * tuple_insert and multi_insert with a BulkInsertState specified. This - * e.g. may e.g. used to flush the relation when inserting with - * TABLE_INSERT_SKIP_WAL specified. + * tuple_insert and multi_insert with a BulkInsertState specified. */ static inline void table_finish_bulk_insert(Relation rel, int options) |