<para>

For more on replication slots,

see <xref linkend="streaming-replication-slots">.

see <xref linkend="streaming-replication-slots"> and <xref linkend="logicaldecoding">.

</para>

<table>

<entry>The slot type - <literal>physical</> or <literal>logical</></entry>

</row>

<row>

<entry><structfield>plugin</structfield></entry>

<entry><type>text</type></entry>

<entry></entry>

<entry>The basename of the shared object containing the output plugin this logical slot is using, or null for physical slots.</entry>

</row>

<row>

<entry><structfield>datoid</structfield></entry>

<entry><type>oid</type></entry>

</entry>

</row>

<row>

<entry><structfield>xmin</structfield></entry>

<entry><type>xid</type></entry>

<entry></entry>

<entry>The oldest transaction that this slot needs the database to

retain. <literal>VACUUM</literal> cannot remove catalog tuples deleted

by any later transaction.

</entry>

</row>

<row>

<entry><structfield>catalog_xmin</structfield></entry>

<entry><type>xid</type></entry>

<entry></entry>

<entry>The <literal>xmin</literal>, or oldest transaction ID, that this

slot forces to be retained in the system catalogs. </entry>

</row>

<row>

<entry><structfield>restart_lsn</structfield></entry>

<entry><type>pg_lsn</type></entry>

<!ENTITY nls SYSTEM "nls.sgml">

<!ENTITY plhandler SYSTEM "plhandler.sgml">

<!ENTITY fdwhandler SYSTEM "fdwhandler.sgml">

<!ENTITY logicaldecoding SYSTEM "logicaldecoding.sgml">

<!ENTITY protocol SYSTEM "protocol.sgml">

<!ENTITY sources SYSTEM "sources.sgml">

<!ENTITY storage SYSTEM "storage.sgml">

command <literal>DROP_REPLICATION_SLOT</>.

</entry>

</row>

<row>

<entry>

<indexterm>

<primary>pg_create_logical_replication_slot</primary>

</indexterm>

<literal><function>pg_create_logical_replication_slot(<parameter>slotname</parameter> <type>name</type>, <parameter>plugin</parameter> <type>name</type>)</function></literal>

</entry>

<entry>

(<parameter>slotname</parameter> <type>name</type>, <parameter>xlog_position</parameter> <type>pg_lsn</type>)

</entry>

<entry>

Creates a new logical (decoding) replication slot named

<parameter>slotname</parameter> using the output plugin

<parameter>plugin</parameter>. A call to this function has the same

effect as the replication protocol command

<literal>CREATE REPLICATION SLOT ... LOGICAL</literal>.

</entry>

</row>

<row>

<entry>

<indexterm>

<primary>pg_logical_slot_get_changes</primary>

</indexterm>

<literal><function>pg_logical_slot_get_changes(<parameter>slotname</parameter> <type>name</type>, <parameter>upto_lsn</parameter> <type>pg_lsn</type>, <parameter>upto_nchanges</parameter> <type>int</type>, VARIADIC <parameter>options</parameter> <type>text[]</type>)</function></literal>

</entry>

<entry>

(<parameter>location</parameter> <type>pg_lsn</type>, <parameter>xid</parameter> <type>xid</type>, <parameter>data</parameter> <type>text</type>)

</entry>

<entry>

Returns changes in the slot <parameter>slotname</parameter>, starting

from the point at which since changes have been consumed last. If

<parameter>upto_lsn</> and <parameter>upto_nchanges</> are NULL,

logical decoding will continue until end of WAL. If

<parameter>upto_lsn</> is non-NULL, decoding will include only

those transactions which commit prior to the specified LSN. If

<parameter>upto_nchanges</parameter> is non-NULL, decoding will

stop when the number of rows produced by decoding exceeds

the specified value. Note, however, that the actual number of

rows returned may be larger, since this limit is only checked after

adding the rows produced when decoding each new transaction commit.

</entry>

</row>

<row>

<entry>

<indexterm>

<primary>pg_logical_slot_peek_changes</primary>

</indexterm>

<literal><function>pg_logical_slot_peek_changes(<parameter>slotname</parameter> <type>name</type>, <parameter>upto_lsn</parameter> <type>pg_lsn</type>, <parameter>upto_nchanges</parameter> <type>int</type>, VARIADIC <parameter>options</parameter> <type>text[]</type>)</function></literal>

</entry>

<entry>

(<parameter>location</parameter> <type>text</type>, <parameter>xid</parameter> <type>xid</type>, <parameter>data</parameter> <type>text</type>)

</entry>

<entry>

Behaves just like

the <function>pg_logical_slot_get_changes()</function> function,

except that changes are not consumed; that is, they will be returned

again on future calls.

</entry>

</row>

<row>

<entry>

<indexterm>

<primary>pg_logical_slot_get_binary_changes</primary>

</indexterm>

<literal><function>pg_logical_slot_get_binary_changes(<parameter>slotname</parameter> <type>name</type>, <parameter>upto_lsn</parameter> <type>pg_lsn</type>, <parameter>upto_nchanges</parameter> <type>int</type>, VARIADIC <parameter>options</parameter> <type>text[]</type>)</function></literal>

</entry>

<entry>

(<parameter>location</parameter> <type>pg_lsn</type>, <parameter>xid</parameter> <type>xid</type>, <parameter>data</parameter> <type>bytea</type>)

</entry>

<entry>

Behaves just like

the <function>pg_logical_slot_get_changes()</function> function,

except that changes are returned as <type>bytea</type>.

</entry>

</row>

<row>

<entry>

<indexterm>

<primary>pg_logical_slot_peek_binary_changes</primary>

</indexterm>

<literal><function>pg_logical_slot_peek_binary_changes(<parameter>slotname</parameter> <type>name</type>, <parameter>upto_lsn</parameter> <type>pg_lsn</type>, <parameter>upto_nchanges</parameter> <type>int</type>, VARIADIC <parameter>options</parameter> <type>text[]</type>)</function></literal>

</entry>

<entry>

(<parameter>location</parameter> <type>pg_lsn</type>, <parameter>xid</parameter> <type>xid</type>, <parameter>data</parameter> <type>bytea</type>)

</entry>

<entry>

Behaves just like

the <function>pg_logical_slot_get_changes()</function> function,

except that changes are returned as <type>bytea</type> and that

changes are not consumed; that is, they will be returned again

on future calls.

</entry>

</row>

</tbody>

</tgroup>

</table>

</sect2>

<sect2 id="functions-admin-dbobject">