整理了postgresql的系统表关联的常用SQL，如下： ~~~ --查看数据库 select * from pg_database; --查看表空间 select * from pg_tablespace; --查看语言 select * from pg_language; --查看角色用户 select * from pg_user; select * from pg_shadow; select * from pg_roles; --查看会话进程 select * from pg_stat_activity; --查看表 SELECT * FROM pg_tables where schemaname = 'public'; --查看表字段 select * from information_schema.columns where table_schema = 'public' and table_name = 'pf_vip_org'; --查看视图 select * from pg_views where schemaname = 'public'; select * from information_schema.views where table_schema = 'public'; --查看触发器 select * from information_schema.triggers; --查看序列 select * from information_schema.sequences where sequence_schema = 'public'; --查看约束 select * from pg_constraint where contype = 'p' --u unique,p primary,f foreign,c check,t trigger,x exclusion select a.relname as table_name,b.conname as constraint_name,b.contype as constraint_type from pg_class a,pg_constraint b where a.oid = b.conrelid and a.relname = 'cc'; --查看索引 select * from pg_index ; --查看表上存在哪些索引以及大小 select relname,n.amname as index_type from pg_class m,pg_am n where m.relam = n.oid and m.oid in ( select b.indexrelid from pg_class a,pg_index b where a.oid = b.indrelid and a.relname = 'cc'); SELECT c.relname,c2.relname, c2.relpages*8 as size_kb FROM pg_class c, pg_class c2, pg_index i WHERE c.relname = 'cc' AND c.oid = i.indrelid AND c2.oid = i.indexrelid ORDER BY c2.relname; --查看索引定义 select b.indexrelid from pg_class a,pg_index b where a.oid = b.indrelid and a.relname = 'cc'; select pg_get_indexdef(b.indexrelid); --查看过程函数定义 select oid,* from pg_proc where proname = 'insert_platform_action_exist'; --oid = 24610 select * from pg_get_functiondef(24610); --查看表大小(不含索引等信息) select pg_relation_size('cc'); --368640 byte select pg_size_pretty(pg_relation_size('cc')) --360 kB --查看DB大小 select pg_size_pretty(pg_database_size('smiletao')); --12M --查看服务器DB运行状态 [postgres@eyar ~]$ pg_ctl status -D $PGDATA pg_ctl: server is running (PID: 2373) /home/postgres/bin/postgres "-D" "/database/pgdata" --查看每个DB的使用情况(读,写,缓存,更新,事务等) select * from pg_stat_database --查看索引的使用情况 select * from pg_stat_user_indexes; --查看表所对应的数据文件路径与大小 SELECT pg_relation_filepath(oid), relpages FROM pg_class WHERE relname = 'empsalary'; --查看索引与相关字段及大小 SELECT n.nspname AS schema_name, r.rolname as table_owner, bc.relname AS table_name, ic.relname AS index_name, a.attname AS column_name, bc.relpages*8 as index_size_kb FROM pg_namespace n, pg_class bc, -- base class pg_class ic, -- index class pg_index i, pg_attribute a, -- att in base pg_roles r WHERE bc.relnamespace = n.oid and i.indrelid = bc.oid and i.indexrelid = ic.oid and bc.relowner = r.oid and i.indkey[0] = a.attnum and i.indnatts = 1 and a.attrelid = bc.oid and n.nspname = 'public' and bc.relname = 'cc' ORDER BY schema_name, table_name, index_name, attname; --查看PG锁 select * from pg_locks; 备注：relpages*8 是实际所占磁盘大小 --查看表空间大小 select pg_tablespace_size('pg_default'); --查看序列与表的对应关系 WITH fq_objects AS (SELECT c.oid,c.relname AS fqname , c.relkind, c.relname AS relation FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace ), sequences AS (SELECT oid,fqname FROM fq_objects WHERE relkind = 'S'), tables AS (SELECT oid, fqname FROM fq_objects WHERE relkind = 'r' ) SELECT s.fqname AS sequence, '->' as depends, t.fqname AS table FROM pg_depend d JOIN sequences s ON s.oid = d.objid JOIN tables t ON t.oid = d.refobjid WHERE d.deptype = 'a' and t.fqname = 'cc'; ~~~