os: centos 7.4
db: postgresql 10.10
版本
# cat /etc/centos-release
CentOS Linux release 7.4.1708 (Core)
#
# su - postgres
Last login: Sat Oct 26 22:55:25 CST 2019 on pts/0
$
$ psql -c "select version();"
version
----------------------------------------------------------------------------------------------------------
PostgreSQL 10.10 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36), 64-bit
(1 row)
create table
postgres=# select pg_switch_wal();
pg_switch_wal
---------------
4/93A773D0
(1 row)
postgres=# checkpoint;
postgres=# select pg_walfile_name(pg_current_wal_lsn());
pg_walfile_name
--------------------------
000000010000000400000094
(1 row)
postgres=# create table tmp_t3 ( c0 varchar(100),c1 varchar(100),c2 varchar(100));
postgres=# checkpoint;
pg_waldump
對 pg_waldump 使用 --follow 參數,類似 linux 的 tail 參數
$ /usr/pgsql-10/bin/pg_waldump /var/lib/pgsql/10/data/pg_wal/000000010000000400000094 --follow
truncate table
postgres=# truncate table tmp_t3;
postgres=# checkpoint;
pg_waldump 的記錄
rmgr: Heap2 len (rec/tot): 56/ 56, tx: 0, lsn: 4/9402F808, prev 4/9402F7D0, desc: CLEAN remxid 306413, blkref #0: rel 1663/13808/73970 blk 2
rmgr: Standby len (rec/tot): 42/ 42, tx: 306414, lsn: 4/9402F840, prev 4/9402F808, desc: LOCK xid 306414 db 13808 rel 123791
rmgr: Storage len (rec/tot): 42/ 42, tx: 306414, lsn: 4/9402F870, prev 4/9402F840, desc: CREATE base/13808/123795
rmgr: Heap len (rec/tot): 123/ 123, tx: 306414, lsn: 4/9402F8A0, prev 4/9402F870, desc: UPDATE off 4 xmax 306414 ; new off 5 xmax 0, blkref #0: rel 1663/13808/73970 blk 2
rmgr: Btree len (rec/tot): 64/ 64, tx: 306414, lsn: 4/9402F920, prev 4/9402F8A0, desc: INSERT_LEAF off 24, blkref #0: rel 1663/13808/73973 blk 2
rmgr: Btree len (rec/tot): 72/ 72, tx: 306414, lsn: 4/9402F960, prev 4/9402F920, desc: INSERT_LEAF off 103, blkref #0: rel 1663/13808/73974 blk 5
rmgr: Btree len (rec/tot): 64/ 64, tx: 306414, lsn: 4/9402F9A8, prev 4/9402F960, desc: INSERT_LEAF off 162, blkref #0: rel 1663/13808/73975 blk 5
rmgr: Transaction len (rec/tot): 114/ 114, tx: 306414, lsn: 4/9402F9E8, prev 4/9402F9A8, desc: COMMIT 2020-02-29 20:31:49.504025 CST; rels: base/13808/123794; inval msgs: catcache 50 catcache 49 relcache 123791
參考: