KingbaseES V8R6运维案例之---wal日志解析DDL操作
案例说明：
通过sys_waldump解析DDL操作，获取DDL操作的日志条目具体内容。
适用版本：
KingbaseES V8R3/R6
一、DDL事务操作对应的wal日志文件
# 查看当前online的wal日志文件
prod1=# select pg_current_wal_lsn(),pg_walfile_name(pg_current_wal_lsn()),pg_walfile_name_offset(pg_current_wal_lsn());
pg_current_wal_lsn | pg_walfile_name | pg_walfile_name_offset
--------------------+--------------------------+-----------------------------------
4/5C0251D8 | 0000001D000000040000005C | (0000001D000000040000005C,152024)
(1 row)
##如上所示，当前事务操作的wal日志flush到“0000001D000000040000005C”对应的日志文件。
二、sys_waldump解析wal日志
1、执行sys_waldump解析日志
[kingbase@node101 bin]$ ./sys_waldump /data/kingbase/r6ha/data/sys_wal/0000001D000000040000005C -s 4/5C003C70
2、分析“create database”操作日志
test=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C003C70
(1 row)
test=# create database prod1;
CREATE DATABASE
1）如下图所示，“create database”事务对应的rmgr:Database，xid：288，操作类型：create，并从template0模板创建prod1数据库（copy），数据库oid：189186。
2）rmgr：XLOG，操作类型：CHECKPOINT_ONLINE，记录checkpoint对应的日志。fpw true：开启full page write。
3）rmgr:Transaction，操作类型：commit，xid为2882的事务提交，将日志条目从wal buffer同步（sync）到磁盘。
4）rmgr：Standby记录事务的状态信息。
3、分析“ create table”操作日志
prod1=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C004700
(1 row)
prod1=# create table tb1 (id int,name varchar2(10));
CREATE TABLE
prod1=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C024788
(1 row)
1）如下所示：rmgr:Storage对应的表创建，对应的操作：Create，lsn：4/5C004730，xid：2883，filenode：base/189186/189187。
2）创建表后，将更新系统表和视图及系统表的索引。在创建表后的日志条目里记录了对系统表、视图及索引的操作。如rmgr: Heap、rmgr: Btree 等，操作类型：insert。
rmgr: Heap len (rec/tot): 56/ 6703, tx: 2883, lsn: 4/5C004760, prev 4/5C004730, desc: INSERT off 102 flags 0x01, blkref #0: rel 1663/189186/1247 blk 0 FPW
rmgr: Btree len (rec/tot): 55/ 8345, tx: 2883, lsn: 4/5C0061A8, prev 4/5C004760, desc: INSERT_LEAF off 793, blkref #0: rel 1663/189186/2703 blk 1 FPW
rmgr: Btree len (rec/tot): 55/ 11952, tx: 2883, lsn: 4/5C008260, prev 4/5C0061A8, desc: INSERT_LEAF off 715, blkref #0: rel 1663/189186/2704 blk 1 FPW
rmgr: Heap len (rec/tot): 56/ 8138, tx: 2883, lsn: 4/5C00B128, prev 4/5C008260, desc: INSERT off 243 flags 0x01, blkref #0: rel 1663/189186/2608 blk 14 FPW
rmgr: Btree len (rec/tot): 55/ 8783, tx: 2883, lsn: 4/5C00D110, prev 4/5C00B128, desc: INSERT_LEAF off 635, blkref #0: rel 1663/189186/2673 blk 11 FPW
rmgr: Btree len (rec/tot): 55/ 7976, tx: 2883, lsn: 4/5C00F378, prev 4/5C00D110, desc: INSERT_LEAF off 800, blkref #0: rel 1663/189186/2674 blk 17 FPW
rmgr: Heap len (rec/tot): 207/ 207, tx: 2883, lsn: 4/5C0112B8, prev 4/5C00F378, desc: INSERT off 103 flags 0x00, blkref #0: rel 1663/189186/1247 blk 0
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C011388, prev 4/5C0112B8, desc: INSERT_LEAF off 793, blkref #0: rel 1663/189186/2703 blk 1
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C0113C8, prev 4/5C011388, desc: INSERT_LEAF off 103, blkref #0: rel 1663/189186/2704 blk 1
rmgr: Heap len (rec/tot): 80/ 80, tx: 2883, lsn: 4/5C011410, prev 4/5C0113C8, desc: INSERT off 247 flags 0x00, blkref #0: rel 1663/189186/2608 blk 14
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C011460, prev 4/5C011410, desc: INSERT_LEAF off 635, blkref #0: rel 1663/189186/2673 blk 11
rmgr: Btree len (rec/tot): 55/ 10341, tx: 2883, lsn: 4/5C0114A8, prev 4/5C011460, desc: INSERT_LEAF off 1096, blkref #0: rel 1663/189186/2674 blk 7 FPW
rmgr: Heap len (rec/tot): 56/ 3340, tx: 2883, lsn: 4/5C013D28, prev 4/5C0114A8, desc: INSERT off 2 flags 0x01, blkref #0: rel 1663/189186/1259 blk 0 FPW
rmgr: Btree len (rec/tot): 55/ 7685, tx: 2883, lsn: 4/5C014A50, prev 4/5C013D28, desc: INSERT_LEAF off 729, blkref #0: rel 1663/189186/2662 blk 1 FPW
rmgr: Standby len (rec/tot): 46/ 46, tx: 0, lsn: 4/5C016870, prev 4/5C014A50, desc: RUNNING_XACTS nextXid 2884 latestCompletedXid 1543588432 oldestRunningXid 2883
rmgr: Btree len (rec/tot): 55/ 11364, tx: 2883, lsn: 4/5C0168A0, prev 4/5C016870, desc: INSERT_LEAF off 681, blkref #0: rel 1663/189186/2663 blk 1 FPW
rmgr: Btree len (rec/tot): 55/ 6292, tx: 2883, lsn: 4/5C019520, prev 4/5C0168A0, desc: INSERT_LEAF off 673, blkref #0: rel 1663/189186/3455 blk 1 FPW
rmgr: Heap len (rec/tot): 56/ 4147, tx: 2883, lsn: 4/5C01ADD0, prev 4/5C019520, desc: INSERT off 81 flags 0x01, blkref #0: rel 1663/189186/1249 blk 4 FPW
rmgr: Btree len (rec/tot): 55/ 5564, tx: 2883, lsn: 4/5C01BE08, prev 4/5C01ADD0, desc: INSERT_LEAF off 404, blkref #0: rel 1663/189186/2658 blk 8 FPW
rmgr: Btree len (rec/tot): 55/ 3969, tx: 2883, lsn: 4/5C01D3E0, prev 4/5C01BE08, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6 FPW
rmgr: Heap len (rec/tot): 175/ 175, tx: 2883, lsn: 4/5C01E380, prev 4/5C01D3E0, desc: INSERT off 82 flags 0x00, blkref #0: rel 1663/189186/1249 blk 4
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01E430, prev 4/5C01E380, desc: INSERT_LEAF off 405, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01E478, prev 4/5C01E430, desc: INSERT_LEAF off 360, blkref #0: rel 1663/189186/2659 blk 6
rmgr: Heap len (rec/tot): 175/ 175, tx: 2883, lsn: 4/5C01E4B8, prev 4/5C01E478, desc: INSERT off 83 flags 0x00, blkref #0: rel 1663/189186/1249 blk 4
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01E568, prev 4/5C01E4B8, desc: INSERT_LEAF off 404, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01E5B0, prev 4/5C01E568, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6
rmgr: Heap len (rec/tot): 175/ 175, tx: 2883, lsn: 4/5C01E5F0, prev 4/5C01E5B0, desc: INSERT off 84 flags 0x00, blkref #0: rel 1663/189186/1249 blk 4
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01E6A0, prev 4/5C01E5F0, desc: INSERT_LEAF off 407, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01E6E8, prev 4/5C01E6A0, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6
rmgr: Heap len (rec/tot): 175/ 175, tx: 2883, lsn: 4/5C01E728, prev 4/5C01E6E8, desc: INSERT off 86 flags 0x00, blkref #0: rel 1663/189186/1249 blk 4
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01E7D8, prev 4/5C01E728, desc: INSERT_LEAF off 404, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01E820, prev 4/5C01E7D8, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6
rmgr: Heap len (rec/tot): 175/ 175, tx: 2883, lsn: 4/5C01E860, prev 4/5C01E820, desc: INSERT off 88 flags 0x00, blkref #0: rel 1663/189186/1249 blk 4
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01E910, prev 4/5C01E860, desc: INSERT_LEAF off 408, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01E958, prev 4/5C01E910, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6
rmgr: XLOG len (rec/tot): 49/ 491, tx: 2883, lsn: 4/5C01E998, prev 4/5C01E958, desc: FPI_FOR_HINT , blkref #0: rel 1663/189186/1249 fork fsm blk 2 FPW
rmgr: Heap len (rec/tot): 56/ 4800, tx: 2883, lsn: 4/5C01EB88, prev 4/5C01E998, desc: INSERT off 201 flags 0x01, blkref #0: rel 1663/189186/1249 blk 27 FPW
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01FE48, prev 4/5C01EB88, desc: INSERT_LEAF off 404, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01FE90, prev 4/5C01FE48, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6
rmgr: Heap len (rec/tot): 175/ 175, tx: 2883, lsn: 4/5C01FED0, prev 4/5C01FE90, desc: INSERT off 202 flags 0x00, blkref #0: rel 1663/189186/1249 blk 27
rmgr: Btree len (rec/tot): 72/ 72, tx: 2883, lsn: 4/5C01FF80, prev 4/5C01FED0, desc: INSERT_LEAF off 409, blkref #0: rel 1663/189186/2658 blk 8
rmgr: Btree len (rec/tot): 64/ 64, tx: 2883, lsn: 4/5C01FFC8, prev 4/5C01FF80, desc: INSERT_LEAF off 359, blkref #0: rel 1663/189186/2659 blk 6
rmgr: Heap len (rec/tot): 80/ 80, tx: 2883, lsn: 4/5C020020, prev 4/5C01FFC8, desc: INSERT off 534 flags 0x00, blkref #0: rel 1663/189186/2608 blk 14
rmgr: Btree len (rec/tot): 55/ 12130, tx: 2883, lsn: 4/5C020070, prev 4/5C020020, desc: INSERT_LEAF off 712, blkref #0: rel 1663/189186/2673 blk 10 FPW
rmgr: Btree len (rec/tot): 55/ 4590, tx: 2883, lsn: 4/5C022FF0, prev 4/5C020070, desc: INSERT_LEAF off 403, blkref #0: rel 1663/189186/2674 blk 11 FPW
3）更新（update）操作前，需获取对象锁（lock），rmgr: Standby类型记录获取lock的日志条目，操作类型：Lock。
4）当表创建和系统表更新完成后，执行事务的commit。rmgr: Transaction资源类型记录事务commit操作。
5）通过wal日志记录的系统表的oid，可以获取创建表时，需要更新的系统表信息。
prod1=# select oid,relname from sys_class where oid in(1247,2703,2704,2608,2673,2674,1259,2662,2663,3455,1249,2658,2659,1249);
oid | relname
------+-----------------------------------
1247 | pg_type
2658 | pg_attribute_relid_attnam_index
2659 | pg_attribute_relid_attnum_index
2662 | pg_class_oid_index
2663 | pg_class_relname_nsp_index
3455 | pg_class_tblspc_relfilenode_index
2673 | pg_depend_depender_index
2674 | pg_depend_reference_index
2703 | pg_type_oid_index
2704 | pg_type_typname_nsp_index
1249 | pg_attribute
1259 | pg_class
2608 | pg_depend
(13 rows)
3、分析“truncate table”操作日志
prod1=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C0249F8
(1 row)
prod1=# truncate table tb1;
TRUNCATE TABLE
prod1=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C024C50
(1 row)
1）如下图所示：执行‘truncate table’需要在表上获取lock，rmgr: Standby 的资源类型记录获取锁的操作，操作类型：lock。
2）‘truncate table’资源类型：rmgr: Storage，操作类型：Create，只是原对象的filenode“base/189186/189190”被更新。
3）对系统表、视图、索引进行更新。rmgr: Heap 、rmgr: Tree，操作类型：insert、update、clean等。rmgr: Heap2资源类型，对应的操作类型：CLEAN。
4）执行事务的commit，rmgr: Transaction ，操作类型：commit，并记录commit的时间戳。
4、分析“drop table”操作日志
prod1=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C024C50
(1 row)
prod1=# drop table tb1;
DROP TABLE
prod1=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/5C0251D8
(1 row)
1）如下图所示：‘drop table’和‘truncate table’一样，需要获取对象lock。rmgr: Standby资源类型对应的操作：lock。
2）将对象drop后，将会delete系统表中所有的记录。rmgr: Heap，对应的操作为：DELETE
3）drop table后，完成事务的commit；rmgr: Transaction，对应的操作为：COMMIT。
5、分析“create |drop tablespace”操作日志
# 删除表空间操作
prod=# drop tablespace users;
DROP TABLESPACE
prod=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/66006700
(1 row)
# 创建自定义表空间
prod=# create tablespace user_tbs1 location '/data/kingbase/tbs/users';
CREATE TABLESPACE
prod=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
4/66006AA8
(1 row)
test=# select oid,* from sys_tablespace where spcname='user_tbs1';
oid | oid | spcname | spcowner | spcacl | spcoptions
--------+--------+-----------+----------+--------+------------
189205 | 189205 | user_tbs1 | 10 | |
(1 row)
1）如下图所示：‘drop tablespace’对应的资源类型：rmgr: Tablespace，操作类型为：DROP，记录表空间oid。执行完成后，立刻commit。
2）记录系统表更新操作，rmgr: Heap 、Tree，操作类型：INSERT、INSERT_LEAF
3）‘create tablespace’对应的资源类型：rmgr: Tablespace，操作类型：CREATE，创建完成后，事务commit。
三、总结
通过对wal日志的解析，可以加深DDL事务操作的理解及获取事务在wal日志中的具体操作记录信息，可用于数据库事务操作的分析和数据的恢复。
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