U
- unaccent
- unicode_assigned()
- unicode_version()
- unistr()
- unix_socket_directories
- unix_socket_directory
- unix_socket_group
- unix_socket_permissions
- UNLISTEN
- 非日志表
- unnest()
- unsafe_tests
- UPDATE
- update_process_title
- upper()
- upper_inc()
- upper_inf()
- upper(range)
- 用户
- 用户锁
- UUID
- uuid_extract_timestamp()
- uuid_extract_version()
- uuid-ossp