章 49. 系统目录

目录
49.1. 概述
49.2. pg_aggregate
49.3. pg_am
49.4. pg_amop
49.5. pg_amproc
49.6. pg_attrdef
49.7. pg_attribute
49.8. pg_authid
49.9. pg_auth_members
49.10. pg_cast
49.11. pg_class
49.12. pg_collation
49.13. pg_constraint
49.14. pg_conversion
49.15. pg_database
49.16. pg_db_role_setting
49.17. pg_default_acl
49.18. pg_depend
49.19. pg_description
49.20. pg_enum
49.21. pg_event_trigger
49.22. pg_extension
49.23. pg_foreign_data_wrapper
49.24. pg_foreign_server
49.25. pg_foreign_table
49.26. pg_index
49.27. pg_inherits
49.28. pg_language
49.29. pg_largeobject
49.30. pg_largeobject_metadata
49.31. pg_namespace
49.32. pg_opclass
49.33. pg_operator
49.34. pg_opfamily
49.35. pg_pltemplate
49.36. pg_policy
49.37. pg_proc
49.38. pg_range
49.39. pg_replication_origin
49.40. pg_rewrite
49.41. pg_seclabel
49.42. pg_shdepend
49.43. pg_shdescription
49.44. pg_shseclabel
49.45. pg_statistic
49.46. pg_tablespace
49.47. pg_transform
49.48. pg_trigger
49.49. pg_ts_config
49.50. pg_ts_config_map
49.51. pg_ts_dict
49.52. pg_ts_parser
49.53. pg_ts_template
49.54. pg_type
49.55. pg_user_mapping
49.56. 系统视图
49.57. pg_available_extensions
49.58. pg_available_extension_versions
49.59. pg_cursors
49.60. pg_file_settings
49.61. pg_group
49.62. pg_indexes
49.63. pg_locks
49.64. pg_matviews
49.65. pg_policies
49.66. pg_prepared_statements
49.67. pg_prepared_xacts
49.68. pg_replication_origin_status
49.69. pg_replication_slots
49.70. pg_roles
49.71. pg_rules
49.72. pg_seclabels
49.73. pg_settings
49.74. pg_shadow
49.75. pg_stats
49.76. pg_tables
49.77. pg_timezone_abbrevs
49.78. pg_timezone_names
49.79. pg_user
49.80. pg_user_mappings
49.81. pg_views

系统目录是关系型数据库存放模式元数据的地方,比如表和列的信息,以及内部统计信息等。PostgreSQL的系统目录就是普通表。你可以删除并重建这些表、增加列、插入和更新数值, 然后彻底把你的系统搞垮。 通常情况下,我们不应该手工修改系统目录,总有SQL命令可以做这些事情。(例如,CREATE DATABASEpg_database表插入一行 — 并且实际上在磁盘上创建该数据库。) 有几种特别深奥的操作例外,比如增加索引访问方法。