1.在psql中可以使用/dS（区分大小写）查看系统表，如下：

关联列表
/xBC芄/xB9模式 | 名/xB3 | 型/xB1 | 拥有者
------------+--------------------------+--------+----------
pg_catalog | pg_aggregate | 资料/xB1 | postgres
pg_catalog | pg_am | 资料/xB1 | postgres
pg_catalog | pg_amop | 资料/xB1 | postgres
pg_catalog | pg_amproc | 资料/xB1 | postgres
pg_catalog | pg_attrdef | 资料/xB1 | postgres
pg_catalog | pg_attribute | 资料/xB1 | postgres
pg_catalog | pg_auth_members | 资料/xB1 | postgres
pg_catalog | pg_authid | 资料/xB1 | postgres
pg_catalog | pg_autovacuum | 资料/xB1 | postgres
pg_catalog | pg_cast | 资料/xB1 | postgres
pg_catalog | pg_class | 资料/xB1 | postgres
pg_catalog | pg_constraint | 资料/xB1 | postgres
pg_catalog | pg_conversion | 资料/xB1 | postgres
pg_catalog | pg_cursors | 视/xB9郾 | postgres
pg_catalog | pg_database | 资料/xB1 | postgres
pg_catalog | pg_depend | 资料/xB1 | postgres
pg_catalog | pg_description | 资料/xB1 | postgres
pg_catalog | pg_enum | 资料/xB1 | postgres
pg_catalog | pg_group | 视/xB9郾 | postgres
pg_catalog | pg_index | 资料/xB1 | postgres
pg_catalog | pg_indexes | 视/xB9郾 | postgres
pg_catalog | pg_inherits | 资料/xB1 | postgres
pg_catalog | pg_language | 资料/xB1 | postgres
pg_catalog | pg_largeobject | 资料/xB1 | postgres
pg_catalog | pg_listener | 资料/xB1 | postgres
pg_catalog | pg_locks | 视/xB9郾 | postgres
pg_catalog | pg_namespace | 资料/xB1 | postgres
pg_catalog | pg_opclass | 资料/xB1 | postgres
pg_catalog | pg_operator | 资料/xB1 | postgres
pg_catalog | pg_opfamily | 资料/xB1 | postgres
pg_catalog | pg_pltemplate | 资料/xB1 | postgres
pg_catalog | pg_prepared_statements | 视/xB9郾 | postgres
pg_catalog | pg_prepared_xacts | 视/xB9郾 | postgres
pg_catalog | pg_proc | 资料/xB1 | postgres
pg_catalog | pg_rewrite | 资料/xB1 | postgres
pg_catalog | pg_roles | 视/xB9郾 | postgres
pg_catalog | pg_rules | 视/xB9郾 | postgres
pg_catalog | pg_settings | 视/xB9郾 | postgres
pg_catalog | pg_shadow | 视/xB9郾 | postgres
pg_catalog | pg_shdepend | 资料/xB1 | postgres
pg_catalog | pg_shdescription | 资料/xB1 | postgres
pg_catalog | pg_stat_activity | 视/xB9郾 | postgres
pg_catalog | pg_stat_all_indexes | 视/xB9郾 | postgres
pg_catalog | pg_stat_all_tables | 视/xB9郾 | postgres
pg_catalog | pg_stat_bgwriter | 视/xB9郾 | postgres
pg_catalog | pg_stat_database | 视/xB9郾 | postgres
pg_catalog | pg_stat_sys_indexes | 视/xB9郾 | postgres
pg_catalog | pg_stat_sys_tables | 视/xB9郾 | postgres
pg_catalog | pg_stat_user_indexes | 视/xB9郾 | postgres
pg_catalog | pg_stat_user_tables | 视/xB9郾 | postgres
pg_catalog | pg_statio_all_indexes | 视/xB9郾 | postgres
pg_catalog | pg_statio_all_sequences | 视/xB9郾 | postgres
pg_catalog | pg_statio_all_tables | 视/xB9郾 | postgres
pg_catalog | pg_statio_sys_indexes | 视/xB9郾 | postgres
pg_catalog | pg_statio_sys_sequences | 视/xB9郾 | postgres
pg_catalog | pg_statio_sys_tables | 视/xB9郾 | postgres
pg_catalog | pg_statio_user_indexes | 视/xB9郾 | postgres
pg_catalog | pg_statio_user_sequences | 视/xB9郾 | postgres
pg_catalog | pg_statio_user_tables | 视/xB9郾 | postgres
pg_catalog | pg_statistic | 资料/xB1 | postgres
pg_catalog | pg_stats | 视/xB9郾 | postgres
pg_catalog | pg_tables | 视/xB9郾 | postgres
pg_catalog | pg_tablespace | 资料/xB1 | postgres
pg_catalog | pg_timezone_abbrevs | 视/xB9郾 | postgres
pg_catalog | pg_timezone_names | 视/xB9郾 | postgres
pg_catalog | pg_trigger | 资料/xB1 | postgres
pg_catalog | pg_ts_config | 资料/xB1 | postgres
pg_catalog | pg_ts_config_map | 资料/xB1 | postgres
pg_catalog | pg_ts_dict | 资料/xB1 | postgres
pg_catalog | pg_ts_parser | 资料/xB1 | postgres
pg_catalog | pg_ts_template | 资料/xB1 | postgres
pg_catalog | pg_type | 资料/xB1 | postgres
pg_catalog | pg_user | 视/xB9郾 | postgres
pg_catalog | pg_views | 视/xB9郾 | postgres
(74 笔资料列)

2.记录数据库信息的基本表pg_database

查看所有数据库名称

select datname from information_schema.database；

3.记录当前数据库所有表的表pg_tables

查询出用户表的sql语句：

select table_name from information_schema.tables where table_schema = 'pub
lic' and table_type = 'BASE TABLE' and is_insertable_into = 'YES';

4.记录当前数据库所有表的所有字段的表pg_columns

查询出指定表article的字段的sql语句：

select column_name,is_nullable,data_type from information_schema.columns where table_name = 'article';

注意，这些表使用时要注明schema，即information_schema