PostgreSQL通过解析日志，获取数据库增量变化，pg_recvlogical

1.首先用该工具来看我们的日志变化，需要先将test_decoding插件编译并安装（进入contrib，编译安装即可）

 

创建一个slot：

SELECT * FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding’);

 

获取slot记录的变更日志：

postgres=# insert into test values(1, 'test', now());

INSERT 0 1

postgres=# insert into test values(1, 'test', now());

INSERT 0 1

 

只获取变化，不消费slot：

postgres=# SELECT * FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL);

    lsn    | xid |                                                             data

-----------+-----+-------------------------------------------------------------------------------------------------------------------------------

 0/16637F8 | 572 | BEGIN 572

 0/16637F8 | 572 | table public.test: INSERT: id[integer]:1 info[text]:'test' crt_time[timestamp without time zone]:'2019-05-27 11:52:08.147527'

 0/1663B20 | 572 | COMMIT 572

 0/1663B58 | 573 | BEGIN 573

 0/1663B58 | 573 | table public.test: INSERT: id[integer]:1 info[text]:'test' crt_time[timestamp without time zone]:'2019-05-27 11:52:09.67556'

 0/1663BD8 | 573 | COMMIT 573

(6 rows)

postgres=# select * from pg_replication