postgresql常用SQL

1. --查看数据库
2. select * from pg_database;
3. --查看表空间
4. select * from pg_tablespace;
5. --查看语言
6. select * from pg_language;
7. --查看角色用户
8. select * from pg_user;
9. select * from pg_shadow;
10. select * from pg_roles;
11. --查看会话进程
12. select * from pg_stat_activity;
13. --查看表
14. SELECT * FROM pg_tables where schemaname = 'public';
15. --查看表字段
16. select * from information_schema.columns where table_schema = 'public' and table_name = 'pf_vip_org';
17. --查看视图
18. select * from pg_views where schemaname = 'public';
19. select * from information_schema.views where table_schema = 'public';
20. --查看触发器
21. select * from information_schema.triggers;
22. --查看序列
23. select * from information_schema.sequences where sequence_schema = 'public';
24. --查看约束
25. select * from pg_constraint where contype = 'p'
26. --u unique,p primary,f foreign,c check,t trigger,x exclusion
27. 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';
28. --查看索引
29. select * from pg_index ;
30. --查看表上存在哪些索引以及大小
31. select relname,n.amname as index_type from pg_class m,pg_am n where m.relam = n.oid and m.oid in (
32. select b.indexrelid from pg_class a,pg_index b where a.oid = b.indrelid and a.relname = 'cc');
33. SELECT c.relname,c2.relname, c2.relpages*8 as size_kb
34. FROM pg_class c, pg_class c2, pg_index i
35. WHERE c.relname = 'cc' AND
36. c.oid = i.indrelid AND
37. c2.oid = i.indexrelid
38. ORDER BY c2.relname;
39. --查看索引定义
40. select b.indexrelid from pg_class a,pg_index b where a.oid = b.indrelid and a.relname = 'cc';
41. select pg_get_indexdef(b.indexrelid);
42. --查看过程函数定义
43. select oid,* from pg_proc where proname = 'insert_platform_action_exist'; --oid = 24610
44. select * from pg_get_functiondef(24610);
45. --查看表大小(不含索引等信息)
46. select pg_relation_size('cc');                         --368640 byte
47. select pg_size_pretty(pg_relation_size('cc'))   --360 kB
48. --查看DB大小
49. select pg_size_pretty(pg_database_size('smiletao'));   --12M
50. --查看服务器DB运行状态
51. [postgres@eyar ~]$ pg_ctl status -D $PGDATA
52. pg_ctl: server is running (PID: 2373)
53. /home/postgres/bin/postgres "-D" "/database/pgdata"
54. --查看每个DB的使用情况(读,写,缓存,更新,事务等)
55. select * from pg_stat_database
56. --查看索引的使用情况
57. select * from pg_stat_user_indexes;
58. --查看表所对应的数据文件路径与大小
59. SELECT pg_relation_filepath(oid), relpages FROM pg_class WHERE relname = 'empsalary';
60. --查看索引与相关字段及大小
61. SELECT n.nspname AS schema_name,
62. r.rolname as table_owner,
63. bc.relname AS table_name,
64. ic.relname AS index_name,
65. a.attname  AS column_name,
66. bc.relpages*8 as index_size_kb
67. FROM pg_namespace n,
68. pg_class bc,             -- base class
69. pg_class ic,             -- index class
70. pg_index i,
71. pg_attribute a,           -- att in base
72. pg_roles r
73. WHERE bc.relnamespace = n.oid
74. and i.indrelid = bc.oid
75. and i.indexrelid = ic.oid
76. and bc.relowner = r.oid
77. and i.indkey[0] = a.attnum
78. and i.indnatts = 1
79. and a.attrelid = bc.oid
80. and n.nspname = 'public'
81. and bc.relname = 'cc'
82. ORDER BY schema_name, table_name, index_name, attname;
83. --查看PG锁
84. select * from pg_locks;
85. 备注：relpages*8 是实际所占磁盘大小
86. --查看表空间大小
87. select pg_tablespace_size('pg_default');
88. --查看序列与表的对应关系
89. WITH fq_objects AS (SELECT c.oid,c.relname AS fqname ,
90. c.relkind, c.relname AS relation
91. FROM pg_class c JOIN pg_namespace n ON n.oid = c.relnamespace ),
92. sequences AS (SELECT oid,fqname FROM fq_objects WHERE relkind = 'S'),
93. tables    AS (SELECT oid, fqname FROM fq_objects WHERE relkind = 'r' )
94. SELECT
95. s.fqname AS sequence,
96. '->' as depends,
97. t.fqname AS table
98. FROM
99. pg_depend d JOIN sequences s ON s.oid = d.objid
100. JOIN tables t ON t.oid = d.refobjid
101. WHERE
102. d.deptype = 'a' and t.fqname = 'cc';