1. 查看所有数据库
sql">\l或
sql">SELECT datname FROM pg_database;2. 查看当前数据库中的所有表
sql">\dt或
sql">SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';3. 查看所有表空间
sql">\db或
sql">SELECT spcname FROM pg_tablespace;4. 查看所有用户（角色）
sql">\du或
sql">SELECT usename FROM pg_user;5. 查看当前数据库的连接信息
sql">SELECT * FROM pg_stat_activity;6. 查看表的详细信息（包括列、类型等）
sql">\d table_name或
sql">SELECT column_name, data_type, is_nullable FROM information_schema.columns WHERE table_name = 'table_name';7. 查看表的索引
sql">\di或
sql">SELECT indexname, indexdef FROM pg_indexes WHERE tablename = 'table_name';8. 查看表的约束
sql">\d+ table_name或
sql">SELECT constraint_name, constraint_type FROM information_schema.table_constraints WHERE table_name = 'table_name';9. 查看当前数据库的大小
sql">SELECT pg_size_pretty(pg_database_size(current_database()));10. 查看表的大小
sql">SELECT pg_size_pretty(pg_total_relation_size('table_name'));11. 查看当前用户
sql">SELECT current_user;12. 查看当前数据库
sql">SELECT current_database();13. 查看所有模式（schema）
sql">\dn或
sql">SELECT schema_name FROM information_schema.schemata;14. 查看所有函数
sql">\df或
sql">SELECT routine_name FROM information_schema.routines WHERE routine_type = 'FUNCTION';15. 查看所有视图
sql">\dv或
sql">SELECT table_name FROM information_schema.views;16. 查看所有触发器
sql">\dy或
sql">SELECT trigger_name FROM information_schema.triggers;17. 查看所有序列
sql">\ds或
sql">SELECT sequence_name FROM information_schema.sequences;18. 查看所有扩展（extensions）
sql">\dx或
sql">SELECT extname FROM pg_extension;19. 查看当前数据库的配置参数
sql">SHOW ALL;20. 查看某个配置参数的值
sql">SHOW parameter_name;21. 查看当前数据库的锁信息
sql">SELECT * FROM pg_locks;22. 查看当前数据库的统计信息
sql">SELECT * FROM pg_stat_all_tables;23. 查看当前数据库的复制状态
sql">SELECT * FROM pg_stat_replication;24. 查看当前数据库的 WAL（Write-Ahead Logging）信息
sql">SELECT * FROM pg_stat_wal;25. 查看当前数据库的备份信息
sql">SELECT * FROM pg_stat_backup;
