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<?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>54.19. pg_replication_slots</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="view-pg-replication-origin-status.html" title="54.18. pg_replication_origin_status" /><link rel="next" href="view-pg-roles.html" title="54.20. pg_roles" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">54.19. <code class="structname">pg_replication_slots</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="view-pg-replication-origin-status.html" title="54.18. pg_replication_origin_status">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="views.html" title="Chapter 54. System Views">Up</a></td><th width="60%" align="center">Chapter 54. System Views</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="view-pg-roles.html" title="54.20. pg_roles">Next</a></td></tr></table><hr /></div><div class="sect1" id="VIEW-PG-REPLICATION-SLOTS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">54.19. <code class="structname">pg_replication_slots</code> <a href="#VIEW-PG-REPLICATION-SLOTS" class="id_link">#</a></h2></div></div></div><a id="id-1.10.5.23.2" class="indexterm"></a><p> The <code class="structname">pg_replication_slots</code> view provides a listing of all replication slots that currently exist on the database cluster, along with their current state. </p><p> For more on replication slots, see <a class="xref" href="warm-standby.html#STREAMING-REPLICATION-SLOTS" title="27.2.6. Replication Slots">Section 27.2.6</a> and <a class="xref" href="logicaldecoding.html" title="Chapter 49. Logical Decoding">Chapter 49</a>. </p><div class="table" id="id-1.10.5.23.5"><p class="title"><strong>Table 54.19. <code class="structname">pg_replication_slots</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_replication_slots Columns" border="1"><colgroup><col /></colgroup><thead><tr><th class="catalog_table_entry"><p class="column_definition"> Column Type </p> <p> Description </p></th></tr></thead><tbody><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">slot_name</code> <code class="type">name</code> </p> <p> A unique, cluster-wide identifier for the replication slot </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">plugin</code> <code class="type">name</code> </p> <p> The base name of the shared object containing the output plugin this logical slot is using, or null for physical slots. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">slot_type</code> <code class="type">text</code> </p> <p> The slot type: <code class="literal">physical</code> or <code class="literal">logical</code> </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">datoid</code> <code class="type">oid</code> (references <a class="link" href="catalog-pg-database.html" title="53.15. pg_database"><code class="structname">pg_database</code></a>.<code class="structfield">oid</code>) </p> <p> The OID of the database this slot is associated with, or null. Only logical slots have an associated database. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">database</code> <code class="type">name</code> (references <a class="link" href="catalog-pg-database.html" title="53.15. pg_database"><code class="structname">pg_database</code></a>.<code class="structfield">datname</code>) </p> <p> The name of the database this slot is associated with, or null. Only logical slots have an associated database. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">temporary</code> <code class="type">bool</code> </p> <p> True if this is a temporary replication slot. Temporary slots are not saved to disk and are automatically dropped on error or when the session has finished. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">active</code> <code class="type">bool</code> </p> <p> True if this slot is currently actively being used </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">active_pid</code> <code class="type">int4</code> </p> <p> The process ID of the session using this slot if the slot is currently actively being used. <code class="literal">NULL</code> if inactive. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">xmin</code> <code class="type">xid</code> </p> <p> The oldest transaction that this slot needs the database to retain. <code class="literal">VACUUM</code> cannot remove tuples deleted by any later transaction. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">catalog_xmin</code> <code class="type">xid</code> </p> <p> The oldest transaction affecting the system catalogs that this slot needs the database to retain. <code class="literal">VACUUM</code> cannot remove catalog tuples deleted by any later transaction. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">restart_lsn</code> <code class="type">pg_lsn</code> </p> <p> The address (<code class="literal">LSN</code>) of oldest WAL which still might be required by the consumer of this slot and thus won't be automatically removed during checkpoints unless this LSN gets behind more than <a class="xref" href="runtime-config-replication.html#GUC-MAX-SLOT-WAL-KEEP-SIZE">max_slot_wal_keep_size</a> from the current LSN. <code class="literal">NULL</code> if the <code class="literal">LSN</code> of this slot has never been reserved. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">confirmed_flush_lsn</code> <code class="type">pg_lsn</code> </p> <p> The address (<code class="literal">LSN</code>) up to which the logical slot's consumer has confirmed receiving data. Data corresponding to the transactions committed before this <code class="literal">LSN</code> is not available anymore. <code class="literal">NULL</code> for physical slots. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">wal_status</code> <code class="type">text</code> </p> <p> Availability of WAL files claimed by this slot. Possible values are: </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="literal">reserved</code> means that the claimed files are within <code class="varname">max_wal_size</code>.</p></li><li class="listitem"><p><code class="literal">extended</code> means that <code class="varname">max_wal_size</code> is exceeded but the files are still retained, either by the replication slot or by <code class="varname">wal_keep_size</code>. </p></li><li class="listitem"><p> <code class="literal">unreserved</code> means that the slot no longer retains the required WAL files and some of them are to be removed at the next checkpoint. This state can return to <code class="literal">reserved</code> or <code class="literal">extended</code>. </p></li><li class="listitem"><p> <code class="literal">lost</code> means that some required WAL files have been removed and this slot is no longer usable. </p></li></ul></div><p> The last two states are seen only when <a class="xref" href="runtime-config-replication.html#GUC-MAX-SLOT-WAL-KEEP-SIZE">max_slot_wal_keep_size</a> is non-negative. If <code class="structfield">restart_lsn</code> is NULL, this field is null. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">safe_wal_size</code> <code class="type">int8</code> </p> <p> The number of bytes that can be written to WAL such that this slot is not in danger of getting in state "lost". It is NULL for lost slots, as well as if <code class="varname">max_slot_wal_keep_size</code> is <code class="literal">-1</code>. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">two_phase</code> <code class="type">bool</code> </p> <p> True if the slot is enabled for decoding prepared transactions. Always false for physical slots. </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> <code class="structfield">conflicting</code> <code class="type">bool</code> </p> <p> True if this logical slot conflicted with recovery (and so is now invalidated). Always NULL for physical slots. </p></td></tr></tbody></table></div></div><br class="table-break" /></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="view-pg-replication-origin-status.html" title="54.18. pg_replication_origin_status">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="views.html" title="Chapter 54. System Views">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="view-pg-roles.html" title="54.20. pg_roles">Next</a></td></tr><tr><td width="40%" align="left" valign="top">54.18. <code class="structname">pg_replication_origin_status</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 54.20. <code class="structname">pg_roles</code></td></tr></table></div></body></html>