PostgreSQL 常用运维SQL整理

一、查询并杀会话

|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| -- 查询会话 select pid,usename,client_addr,client_port,query_start,query,wait_event ``from pg_stat_activity; -- 杀会话 select pg_terminate_backend(``'pid号'``); |

|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| -- 使用如下命令自动生成杀会话语句 select datid,datname,pid,usesysid,usename,application_name,client_addr,client_port,state,query,``'select pg_terminate_backend('``||pid||``');' kill_pid ``from pg_stat_activity; |

|----------------------------------------------------------------------------------------------------------|
| -- 杀状态是空闲会话 select pg_terminate_backend(pid) ``from pg_stat_activity ``where state=``'idle'``; |

|----------------------------------------------------------------------------------------|
| -- 查询进程杀会话 select pid,state ``from pg_stat_activity; -- 然后通过 kill -9 pid 杀会话 |

二、查看库-表-schema大小

1) 查看表空间大小

|------------------------------------------------------------------|
| select pg_size_pretty(pg_tablespace_size(``'pg_default'``)); |

2）查看所有数据库大小

|---------------------------------------------------------------------------------|
| select pg_size_pretty(``sum``(pg_database_size(oid))) ``from pg_database; |

3）查看每个数据库大小

|--------------------------------------------------------------------------------|
| select datname,pg_size_pretty(pg_database_size(oid)) ``from pg_database; |

4）查看指定数据库大小

|-----------------------------------------------------------|
| select pg_size_pretty(pg_database_size(``'db_hr'``)); |

5）查看每个schema大小

6）查看所有表大小并大小排序

|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| select tableowner,schemaname,tablename,pg_table_size(schemaname||``'.'``||tablename) ``as table_size ``from pg_tables ``order by table_size ``desc``; |

查看指定schema下所有表大小

查看单张表大小

查看表分区大小

|--------------------------------------------------------------------|
| select pg_size_pretty(pg_partition_size(``'表名'``,``' 分区名'``)); |

三、查询清理事务槽

1) 查询流复制槽

select pg_wal_lsn_diff(pg_current_wal_lsn(),restart_lsn), * ``from pg_replication_slots;

2) 清理流复制槽

xxxdb=# \c xxx

You are now connected ``to database "xxx" as user "antdb"``.

xxx=# ``SELECT pg_drop_replication_slot(``'test_decoding'``);

xxx=# ``checkpoint ; ``--- 要执行checkpoint

四、清理归档日志

可以使用pg_archivecleanup /xxx/xxx目录最旧文件

通过 pg_controldata $PGDATA 命令查询检查点以前xlog文件，可以清理：如：

折叠源码

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| [antdb@opensource``-db ~]$ pg_controldata ``-D /database/antdb pg_controldata: fatal: could not open file ``"/database/antdb/global/pg_control" for reading: No such file or directory [antdb@opensource``-db ~]$ pg_controldata ``-D /database/antdb/data pg_control version number: 1300 Catalog version number: 202007201 Database system identifier: 7265663343146682289 Database cluster state: in production pg_control last modified: Fri 11 Aug 2023 01:18:33 PM CST Latest checkpoint location: 1F/5D1CFFD8 Latest checkpoint's REDO location: 1F/5D1CFFA0 Latest checkpoint's REDO WAL file: 000000010000001F0000005D Latest checkpoint's TimeLineID: 1 Latest checkpoint's PrevTimeLineID: 1 Latest checkpoint's full_page_writes: on Latest checkpoint's NextXID: 0:6059616 Latest checkpoint's NextOID: 24577 Latest checkpoint's NextMultiXactId: 1 Latest checkpoint's NextMultiOffset: 0 Latest checkpoint's oldestXID: 628 Latest checkpoint``'s oldestXID'``s DB: 1 Latest checkpoint's oldestActiveXID: 6059616 Latest checkpoint's oldestMultiXid: 1 Latest checkpoint``'s oldestMulti'``s DB: 1 Latest checkpoint's oldestCommitTsXid:0 Latest checkpoint's newestCommitTsXid:0 Time of latest checkpoint: Fri 11 Aug 2023 01:18:24 PM CST Fake LSN counter for unlogged rels: 0/3E8 Minimum recovery ending location: 0/0 Min recovery ending loc's timeline: 0 Backup start location: 0/0 Backup end location: 0/0 End``-of``-backup record required: no wal_level setting: logical wal_log_hints setting: on max_connections setting: 15000 max_worker_processes setting: 250 max_wal_senders setting: 64 max_prepared_xacts setting: 15000 max_locks_per_xact setting: 256 track_commit_timestamp setting: off Maximum data alignment: 8 Database block size: 8192 Blocks per segment of large relation: 524288 WAL block size: 65536 Bytes per WAL segment: 16777216 Maximum length of identifiers: 64 Maximum columns in an index: 32 Maximum size of a TOAST chunk: 1996 Size of a large``-object chunk: 2048 Date/time ``type storage: 64``-bit integers Float8 argument passing: by value Data page checksum version: 0 Mock authentication nonce: 6b5a172bd5b19f946299ec8858f522c45266783226874df6aec06a0b9840e561 |

然后可以使用 g_archivecleanup /database/antdb/data/pg_wal/ 000000010000001F0000005D 清理之前的日志