> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/16/internals/54.-system-views/overview.md). # 54.1. Overview [Table 54.1](https://www.postgresql.org/docs/current/views-overview.html#VIEW-TABLE) lists the system views. More detailed documentation of each catalog follows below. Except where noted, all the views described here are read-only. #### **Table 54.1. System Views** | View Name | Purpose | | ---------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------- | | [`pg_available_extensions`](https://www.postgresql.org/docs/current/view-pg-available-extensions.html) | available extensions | | [`pg_available_extension_versions`](https://www.postgresql.org/docs/current/view-pg-available-extension-versions.html) | available versions of extensions | | [`pg_backend_memory_contexts`](https://www.postgresql.org/docs/current/view-pg-backend-memory-contexts.html) | backend memory contexts | | [`pg_config`](https://www.postgresql.org/docs/current/view-pg-config.html) | compile-time configuration parameters | | [`pg_cursors`](https://www.postgresql.org/docs/current/view-pg-cursors.html) | open cursors | | [`pg_file_settings`](https://www.postgresql.org/docs/current/view-pg-file-settings.html) | summary of configuration file contents | | [`pg_group`](https://www.postgresql.org/docs/current/view-pg-group.html) | groups of database users | | [`pg_hba_file_rules`](https://www.postgresql.org/docs/current/view-pg-hba-file-rules.html) | summary of client authentication configuration file contents | | [`pg_ident_file_mappings`](https://www.postgresql.org/docs/current/view-pg-ident-file-mappings.html) | summary of client user name mapping configuration file contents | | [`pg_indexes`](https://www.postgresql.org/docs/current/view-pg-indexes.html) | indexes | | [`pg_locks`](https://www.postgresql.org/docs/current/view-pg-locks.html) | locks currently held or awaited | | [`pg_matviews`](https://www.postgresql.org/docs/current/view-pg-matviews.html) | materialized views | | [`pg_policies`](https://www.postgresql.org/docs/current/view-pg-policies.html) | policies | | [`pg_prepared_statements`](https://www.postgresql.org/docs/current/view-pg-prepared-statements.html) | prepared statements | | [`pg_prepared_xacts`](https://www.postgresql.org/docs/current/view-pg-prepared-xacts.html) | prepared transactions | | [`pg_publication_tables`](https://www.postgresql.org/docs/current/view-pg-publication-tables.html) | publications and information of their associated tables | | [`pg_replication_origin_status`](https://www.postgresql.org/docs/current/view-pg-replication-origin-status.html) | information about replication origins, including replication progress | | [`pg_replication_slots`](https://www.postgresql.org/docs/current/view-pg-replication-slots.html) | replication slot information | | [`pg_roles`](https://www.postgresql.org/docs/current/view-pg-roles.html) | database roles | | [`pg_rules`](https://www.postgresql.org/docs/current/view-pg-rules.html) | rules | | [`pg_seclabels`](https://www.postgresql.org/docs/current/view-pg-seclabels.html) | security labels | | [`pg_sequences`](https://www.postgresql.org/docs/current/view-pg-sequences.html) | sequences | | [`pg_settings`](https://www.postgresql.org/docs/current/view-pg-settings.html) | parameter settings | | [`pg_shadow`](https://www.postgresql.org/docs/current/view-pg-shadow.html) | database users | | [`pg_shmem_allocations`](https://www.postgresql.org/docs/current/view-pg-shmem-allocations.html) | shared memory allocations | | [`pg_stats`](https://www.postgresql.org/docs/current/view-pg-stats.html) | planner statistics | | [`pg_stats_ext`](https://www.postgresql.org/docs/current/view-pg-stats-ext.html) | extended planner statistics | | [`pg_stats_ext_exprs`](https://www.postgresql.org/docs/current/view-pg-stats-ext-exprs.html) | extended planner statistics for expressions | | [`pg_tables`](https://www.postgresql.org/docs/current/view-pg-tables.html) | tables | | [`pg_timezone_abbrevs`](https://www.postgresql.org/docs/current/view-pg-timezone-abbrevs.html) | time zone abbreviations | | [`pg_timezone_names`](https://www.postgresql.org/docs/current/view-pg-timezone-names.html) | time zone names | | [`pg_user`](https://www.postgresql.org/docs/current/view-pg-user.html) | database users | | [`pg_user_mappings`](https://www.postgresql.org/docs/current/view-pg-user-mappings.html) | user mappings | | [`pg_views`](https://www.postgresql.org/docs/current/view-pg-views.html) | views | --- # Agent Instructions This documentation is published with GitBook. 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