<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 52. System Catalogs</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="executor.html" title="51.6. Executor" /><link rel="next" href="catalogs-overview.html" title="52.1. Overview" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">Chapter 52. System Catalogs</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="executor.html" title="51.6. Executor">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="internals.html" title="Part VII. Internals">Up</a></td><th width="60%" align="center">Part VII. Internals</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="catalogs-overview.html" title="52.1. Overview">Next</a></td></tr></table><hr></hr></div><div class="chapter" id="CATALOGS"><div class="titlepage"><div><div><h2 class="title">Chapter 52. System Catalogs</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="sect1"><a href="catalogs-overview.html">52.1. Overview</a></span></dt><dt><span class="sect1"><a href="catalog-pg-aggregate.html">52.2. <code class="structname">pg_aggregate</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-am.html">52.3. <code class="structname">pg_am</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-amop.html">52.4. <code class="structname">pg_amop</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-amproc.html">52.5. <code class="structname">pg_amproc</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-attrdef.html">52.6. <code class="structname">pg_attrdef</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-attribute.html">52.7. <code class="structname">pg_attribute</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-authid.html">52.8. <code class="structname">pg_authid</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-auth-members.html">52.9. <code class="structname">pg_auth_members</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-cast.html">52.10. <code class="structname">pg_cast</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-class.html">52.11. <code class="structname">pg_class</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-collation.html">52.12. <code class="structname">pg_collation</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-constraint.html">52.13. <code class="structname">pg_constraint</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-conversion.html">52.14. <code class="structname">pg_conversion</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-database.html">52.15. <code class="structname">pg_database</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-db-role-setting.html">52.16. <code class="structname">pg_db_role_setting</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-default-acl.html">52.17. <code class="structname">pg_default_acl</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-depend.html">52.18. <code class="structname">pg_depend</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-description.html">52.19. <code class="structname">pg_description</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-enum.html">52.20. <code class="structname">pg_enum</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-event-trigger.html">52.21. <code class="structname">pg_event_trigger</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-extension.html">52.22. <code class="structname">pg_extension</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-foreign-data-wrapper.html">52.23. <code class="structname">pg_foreign_data_wrapper</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-foreign-server.html">52.24. <code class="structname">pg_foreign_server</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-foreign-table.html">52.25. <code class="structname">pg_foreign_table</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-index.html">52.26. <code class="structname">pg_index</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-inherits.html">52.27. <code class="structname">pg_inherits</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-init-privs.html">52.28. <code class="structname">pg_init_privs</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-language.html">52.29. <code class="structname">pg_language</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-largeobject.html">52.30. <code class="structname">pg_largeobject</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-largeobject-metadata.html">52.31. <code class="structname">pg_largeobject_metadata</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-namespace.html">52.32. <code class="structname">pg_namespace</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-opclass.html">52.33. <code class="structname">pg_opclass</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-operator.html">52.34. <code class="structname">pg_operator</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-opfamily.html">52.35. <code class="structname">pg_opfamily</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-partitioned-table.html">52.36. <code class="structname">pg_partitioned_table</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-pltemplate.html">52.37. <code class="structname">pg_pltemplate</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-policy.html">52.38. <code class="structname">pg_policy</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-proc.html">52.39. <code class="structname">pg_proc</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-publication.html">52.40. <code class="structname">pg_publication</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-publication-rel.html">52.41. <code class="structname">pg_publication_rel</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-range.html">52.42. <code class="structname">pg_range</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-replication-origin.html">52.43. <code class="structname">pg_replication_origin</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-rewrite.html">52.44. <code class="structname">pg_rewrite</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-seclabel.html">52.45. <code class="structname">pg_seclabel</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-sequence.html">52.46. <code class="structname">pg_sequence</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-shdepend.html">52.47. <code class="structname">pg_shdepend</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-shdescription.html">52.48. <code class="structname">pg_shdescription</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-shseclabel.html">52.49. <code class="structname">pg_shseclabel</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-statistic.html">52.50. <code class="structname">pg_statistic</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-statistic-ext.html">52.51. <code class="structname">pg_statistic_ext</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-subscription.html">52.52. <code class="structname">pg_subscription</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-subscription-rel.html">52.53. <code class="structname">pg_subscription_rel</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-tablespace.html">52.54. <code class="structname">pg_tablespace</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-transform.html">52.55. <code class="structname">pg_transform</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-trigger.html">52.56. <code class="structname">pg_trigger</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-ts-config.html">52.57. <code class="structname">pg_ts_config</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-ts-config-map.html">52.58. <code class="structname">pg_ts_config_map</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-ts-dict.html">52.59. <code class="structname">pg_ts_dict</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-ts-parser.html">52.60. <code class="structname">pg_ts_parser</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-ts-template.html">52.61. <code class="structname">pg_ts_template</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-type.html">52.62. <code class="structname">pg_type</code></a></span></dt><dt><span class="sect1"><a href="catalog-pg-user-mapping.html">52.63. <code class="structname">pg_user_mapping</code></a></span></dt><dt><span class="sect1"><a href="views-overview.html">52.64. System Views</a></span></dt><dt><span class="sect1"><a href="view-pg-available-extensions.html">52.65. <code class="structname">pg_available_extensions</code></a></span></dt><dt><span class="sect1"><a href="view-pg-available-extension-versions.html">52.66. <code class="structname">pg_available_extension_versions</code></a></span></dt><dt><span class="sect1"><a href="view-pg-config.html">52.67. <code class="structname">pg_config</code></a></span></dt><dt><span class="sect1"><a href="view-pg-cursors.html">52.68. <code class="structname">pg_cursors</code></a></span></dt><dt><span class="sect1"><a href="view-pg-file-settings.html">52.69. <code class="structname">pg_file_settings</code></a></span></dt><dt><span class="sect1"><a href="view-pg-group.html">52.70. <code class="structname">pg_group</code></a></span></dt><dt><span class="sect1"><a href="view-pg-hba-file-rules.html">52.71. <code class="structname">pg_hba_file_rules</code></a></span></dt><dt><span class="sect1"><a href="view-pg-indexes.html">52.72. <code class="structname">pg_indexes</code></a></span></dt><dt><span class="sect1"><a href="view-pg-locks.html">52.73. <code class="structname">pg_locks</code></a></span></dt><dt><span class="sect1"><a href="view-pg-matviews.html">52.74. <code class="structname">pg_matviews</code></a></span></dt><dt><span class="sect1"><a href="view-pg-policies.html">52.75. <code class="structname">pg_policies</code></a></span></dt><dt><span class="sect1"><a href="view-pg-prepared-statements.html">52.76. <code class="structname">pg_prepared_statements</code></a></span></dt><dt><span class="sect1"><a href="view-pg-prepared-xacts.html">52.77. <code class="structname">pg_prepared_xacts</code></a></span></dt><dt><span class="sect1"><a href="view-pg-publication-tables.html">52.78. <code class="structname">pg_publication_tables</code></a></span></dt><dt><span class="sect1"><a href="view-pg-replication-origin-status.html">52.79. <code class="structname">pg_replication_origin_status</code></a></span></dt><dt><span class="sect1"><a href="view-pg-replication-slots.html">52.80. <code class="structname">pg_replication_slots</code></a></span></dt><dt><span class="sect1"><a href="view-pg-roles.html">52.81. <code class="structname">pg_roles</code></a></span></dt><dt><span class="sect1"><a href="view-pg-rules.html">52.82. <code class="structname">pg_rules</code></a></span></dt><dt><span class="sect1"><a href="view-pg-seclabels.html">52.83. <code class="structname">pg_seclabels</code></a></span></dt><dt><span class="sect1"><a href="view-pg-sequences.html">52.84. <code class="structname">pg_sequences</code></a></span></dt><dt><span class="sect1"><a href="view-pg-settings.html">52.85. <code class="structname">pg_settings</code></a></span></dt><dt><span class="sect1"><a href="view-pg-shadow.html">52.86. <code class="structname">pg_shadow</code></a></span></dt><dt><span class="sect1"><a href="view-pg-stats.html">52.87. <code class="structname">pg_stats</code></a></span></dt><dt><span class="sect1"><a href="view-pg-tables.html">52.88. <code class="structname">pg_tables</code></a></span></dt><dt><span class="sect1"><a href="view-pg-timezone-abbrevs.html">52.89. <code class="structname">pg_timezone_abbrevs</code></a></span></dt><dt><span class="sect1"><a href="view-pg-timezone-names.html">52.90. <code class="structname">pg_timezone_names</code></a></span></dt><dt><span class="sect1"><a href="view-pg-user.html">52.91. <code class="structname">pg_user</code></a></span></dt><dt><span class="sect1"><a href="view-pg-user-mappings.html">52.92. <code class="structname">pg_user_mappings</code></a></span></dt><dt><span class="sect1"><a href="view-pg-views.html">52.93. <code class="structname">pg_views</code></a></span></dt></dl></div><p> The system catalogs are the place where a relational database management system stores schema metadata, such as information about tables and columns, and internal bookkeeping information. <span class="productname">PostgreSQL</span>'s system catalogs are regular tables. You can drop and recreate the tables, add columns, insert and update values, and severely mess up your system that way. Normally, one should not change the system catalogs by hand, there are normally SQL commands to do that. (For example, <code class="command">CREATE DATABASE</code> inserts a row into the <code class="structname">pg_database</code> catalog — and actually creates the database on disk.) There are some exceptions for particularly esoteric operations, but many of those have been made available as SQL commands over time, and so the need for direct manipulation of the system catalogs is ever decreasing. </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="executor.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="internals.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="catalogs-overview.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">51.6. Executor </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 52.1. Overview</td></tr></table></div></body></html>
