轉載自： http://my.oschina.net/Kenyon/blog/85395
1. 查看數據庫
select * from pg_database;2. 查看錶空間
select * from pg_tablespace;3. 查看語言
select * from pg_language;4. 查看角色用戶
select * from pg_user;
select * from pg_shadow;
select * from pg_roles;5. 查看會話進程
postgres=# select * from pg_stat_activity;
datid | datname | pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | xact_start | query_start | state_change | waiting | state | query
-------+----------+------+----------+----------+------------------+-------------+-----------------+-------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+---------+--------+---------------------------------
12896 | postgres | 2212 | 10 | postgres | psql | | | -1 | 2015-05-07 08:13:30.395563+08 | | 2015-05-07 11:51:33.647046+08 | 2015-05-07 11:51:33.647088+08 | f | idle | end;
12896 | postgres | 4896 | 10 | postgres | psql | | | -1 | 2015-05-07 11:51:55.301628+08 | | 2015-05-07 12:25:39.739174+08 | 2015-05-07 12:25:39.73955+08 | f | idle | select func();
12896 | postgres | 8257 | 10 | postgres | psql | | | -1 | 2015-05-07 16:14:37.431853+08 | 2015-05-07 16:14:38.404417+08 | 2015-05-07 16:14:38.404417+08 | 2015-05-07 16:14:38.404422+08 | f | active | select * from pg_stat_activity;
(3 rows)6. 查看錶
SELECT * FROM pg_tables where schemaname = 'public';7. 查看錶字段的基本信息
postgres=# select * from information_schema.columns where table_schema = 'public' and table_name = 'tb1';
table_catalog | table_schema | table_name | column_name | ordinal_position | column_default | is_nullable | data_type | character_maximum_length | character_octet_length | numeric_precision | numeric_precision_radix | numeric_scale | datetime_precision | interval_type | interval_precision | character_set_catalog | character_set_schema | character_set_name | collation_catalog | collation_schema | collation_name | domain_catalog | domain_schema | domain_name | udt_catalog | udt_schema | udt_name | scope_catalog | scope_schema | scope_name | maximum_cardinality | dtd_identifier | is_self_referencing | is_identity | identity_generation | identity_start | identity_increment | identity_maximum | identity_minimum | identity_cycle | is_generated | generation_expression | is_updatable
---------------+--------------+------------+-------------+------------------+---------------------------------+-------------+-------------------+--------------------------+------------------------+-------------------+-------------------------+---------------+--------------------+---------------+--------------------+-----------------------+----------------------+--------------------+-------------------+------------------+----------------+----------------+---------------+-------------+-------------+------------+----------+---------------+--------------+------------+---------------------+----------------+---------------------+-------------+---------------------+----------------+--------------------+------------------+------------------+----------------+--------------+-----------------------+--------------
postgres | public | tb1 | id | 1 | nextval('tb1_id_seq'::regclass) | NO | integer | | | 32 | 2 | 0 | | | | | | | | | | | | | postgres | pg_catalog | int4 | | | | | 1 | NO | NO | | | | | | | NEVER | | YES
postgres | public | tb1 | name | 2 | | YES | character varying | | 1073741824 | | | | | | | | | | | | | | | | postgres | pg_catalog | varchar | | | | | 2 | NO | NO | | | | | | | NEVER | | YES
(2 rows)8. 查看錶字段的統計信息
postgres=# select * from pg_stats where tablename='tb1';
schemaname | tablename | attname | inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs | histogram_bounds | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram
------------+-----------+---------+-----------+-----------+-----------+------------+------------------+---------------------+---------------------------+-------------+-------------------+------------------------+---------------------
public | tb1 | id | f | 0 | 4 | -1 | | | {1,2,3,4,5,6,7,8,9,10,11} | 0.263636 | | |
public | tb1 | name | f | 0 | 3 | -0.272727 | {aa,cc} | {0.636364,0.272727} | | 1 | | |
(2 rows)9. 查看視圖
postgres=# select * from pg_views where schemaname = 'public';
schemaname | viewname | viewowner | definition
------------+----------+-----------+-----------------------
public | view_tb1 | postgres | SELECT tb1.id, +
| | | tb1.name +
| | | FROM tb1 +
| | | WHERE (tb1.id > 5);
(1 row)postgres=# select * from information_schema.views where table_schema = 'public';
table_catalog | table_schema | table_name | view_definition | check_option | is_updatable | is_insertable_into | is_trigger_updatable | is_trigger_deletable | is_trigger_insertable_into
---------------+--------------+------------+-----------------------+--------------+--------------+--------------------+----------------------+----------------------+----------------------------
postgres | public | view_tb1 | SELECT tb1.id, +| NONE | YES | YES | NO | NO | NO
| | | tb1.name +| | | | | |
| | | FROM tb1 +| | | | | |
| | | WHERE (tb1.id > 5); | | | | | |
(1 row)10. 查看觸發器
postgres=# select * from information_schema.triggers where event_object_table='goods_list';
trigger_catalog | trigger_schema | trigger_name | event_manipulation | event_object_catalog | event_object_schema | event_object_table | action_order | action_condition | action_statement | action_orientation | action_timing | action_reference_old_table | action_reference_new_table | action_reference_old_row | action_reference_new_row | created
-----------------+----------------+-----------------------------+--------------------+----------------------+---------------------+--------------------+--------------+------------------+---------------------------------------------+--------------------+---------------+----------------------------+----------------------------+--------------------------+--------------------------+---------
postgres | public | tri_delete_goods_from_store | UPDATE | postgres | public | goods_list | | | EXECUTE PROCEDURE delete_goods_from_store() | ROW | AFTER | | | | |
(1 row)11. 查看序列
select * from information_schema.sequences where sequence_schema = 'public';12. 查看約束
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';13. 查看索引
select * from pg_index ;14. 查看索引的使用信息
select * from pg_stat_user_indexes;15. 查看錶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 = 'tb1');
SELECT c.relname,c2.relname, c2.relpages*8 as size_kb
FROM pg_class c, pg_class c2, pg_index i
WHERE c.relname = 'tb7' AND
c.oid = i.indrelid AND
c2.oid = i.indexrelid
ORDER BY c2.relname; 16. 查看索引定義
select b.indexrelid from pg_class a,pg_index b where a.oid = b.indrelid and a.relname = 'tb7';
select pg_get_indexdef(b.indexrelid);
postgres=# select pg_get_indexdef('idx_tb7_id'::regclass);
pg_get_indexdef
-------------------------------------------------
CREATE INDEX idx_tb7_id ON tb7 USING btree (id)
(1 row)17. 查看過程函數定義
select oid,* from pg_proc where proname = 'insert_platform_action_exist'; --oid = 24610
select * from pg_get_functiondef(24610);postgres=# select oid from pg_proc where proname='f_test';
oid
-------
57414
57404
(2 rows)
postgres=# select pg_get_functiondef(57404);
pg_get_functiondef
-----------------------------------------------------
CREATE OR REPLACE FUNCTION public.f_test(i integer)+
RETURNS void +
LANGUAGE plpgsql +
AS $function$ +
begin +
update tb1 set name='cc' where id=i; +
end; +
$function$ +
(1 row)18. 查看視圖定義
postgres=# select pg_get_viewdef('view_tb1');
pg_get_viewdef
-----------------------
SELECT tb1.id, +
tb1.name +
FROM tb1 +
WHERE (tb1.id > 5);
(1 row)19. 查看錶大小(不含索引等信息)
select pg_relation_size('cc'); --368640 byte
select pg_size_pretty(pg_relation_size('cc')) --360 kB20. 查看DB大小
select pg_size_pretty(pg_database_size('smiletao')); --12M21. 查看服務器DB運行狀態
[postgres@eyar ~]$ pg_ctl status -D $PGDATA
pg_ctl: server is running (PID: 2373)
/home/postgres/bin/postgres "-D" "/database/pgdata" 22. 查看每個DB的使用情況(讀,寫,緩存,更新,事務等)
select * from pg_stat_database;23. 查看索引的使用情況
select * from pg_stat_user_indexes;24. 查看錶所對應的數據文件路徑與大小
SELECT pg_relation_filepath(oid), relpages FROM pg_class WHERE relname = 'empsalary';25. 查看索引與相關字段及大小
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;26. 查看PG鎖
select * from pg_locks;備註：relpages*8 是實際所佔磁盤大小
27. 查看錶空間大小
select pg_tablespace_size('pg_default');28. 查看序列與表的對應關係
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';