mirror of
https://github.com/postgres/postgres.git
synced 2025-07-27 12:41:57 +03:00
Two-phase commit. Original patch by Heikki Linnakangas, with additional
hacking by Alvaro Herrera and Tom Lane.
This commit is contained in:
Tom Lane
@ -1,6 +1,6 @@
|
||||
<!--
|
||||
Documentation of the system catalogs, directed toward PostgreSQL developers
|
||||
$PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.103 2005/06/13 23:14:47 tgl Exp $
|
||||
$PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.104 2005/06/17 22:32:41 tgl Exp $
|
||||
-->
|
||||
|
||||
<chapter id="catalogs">
|
||||
@ -3932,6 +3932,11 @@
|
||||
<entry>currently held locks</entry>
|
||||
</row>
|
||||
|
||||
<row>
|
||||
<entry><link linkend="view-pg-prepared-xacts"><structname>pg_prepared_xacts</structname></link></entry>
|
||||
<entry>currently prepared transactions</entry>
|
||||
</row>
|
||||
|
||||
<row>
|
||||
<entry><link linkend="view-pg-rules"><structname>pg_rules</structname></link></entry>
|
||||
<entry>rules</entry>
|
||||
@ -4167,8 +4172,10 @@
|
||||
<entry><structfield>pid</structfield></entry>
|
||||
<entry><type>integer</type></entry>
|
||||
<entry></entry>
|
||||
<entry>process ID of the server process holding or awaiting this
|
||||
lock</entry>
|
||||
<entry>
|
||||
Process ID of the server process holding or awaiting this
|
||||
lock. Zero if the lock is held by a prepared transaction.
|
||||
</entry>
|
||||
</row>
|
||||
<row>
|
||||
<entry><structfield>mode</structfield></entry>
|
||||
@ -4250,6 +4257,87 @@
|
||||
|
||||
</sect1>
|
||||
|
||||
<sect1 id="view-pg-prepared-xacts">
|
||||
<title><structname>pg_prepared_xacts</structname></title>
|
||||
|
||||
<indexterm zone="view-pg-prepared-xacts">
|
||||
<primary>pg_prepared_xacts</primary>
|
||||
</indexterm>
|
||||
|
||||
<para>
|
||||
The view <structname>pg_prepared_xacts</structname> displays
|
||||
information about transactions that are currently prepared for two-phase
|
||||
commit (see <xref linkend="sql-prepare-transaction"
|
||||
endterm="sql-prepare-transaction-title"> for details).
|
||||
</para>
|
||||
|
||||
<para>
|
||||
<structname>pg_prepared_xacts</structname> contains one row per prepared
|
||||
transaction. An entry is removed when the transaction is committed or
|
||||
rolled back.
|
||||
</para>
|
||||
|
||||
<table>
|
||||
<title><structname>pg_prepared_xacts</> Columns</title>
|
||||
|
||||
<tgroup cols=4>
|
||||
<thead>
|
||||
<row>
|
||||
<entry>Name</entry>
|
||||
<entry>Type</entry>
|
||||
<entry>References</entry>
|
||||
<entry>Description</entry>
|
||||
</row>
|
||||
</thead>
|
||||
<tbody>
|
||||
<row>
|
||||
<entry><structfield>transaction</structfield></entry>
|
||||
<entry><type>xid</type></entry>
|
||||
<entry></entry>
|
||||
<entry>
|
||||
Numeric transaction identifier of the prepared transaction
|
||||
</entry>
|
||||
</row>
|
||||
<row>
|
||||
<entry><structfield>gid</structfield></entry>
|
||||
<entry><type>text</type></entry>
|
||||
<entry></entry>
|
||||
<entry>
|
||||
Global transaction identifier that was assigned to the transaction
|
||||
</entry>
|
||||
</row>
|
||||
<row>
|
||||
<entry><structfield>owner</structfield></entry>
|
||||
<entry><type>name</type></entry>
|
||||
<entry><literal><link linkend="catalog-pg-shadow"><structname>pg_shadow</structname></link>.usename</literal></entry>
|
||||
<entry>
|
||||
Name of the user that executed the transaction
|
||||
</entry>
|
||||
</row>
|
||||
<row>
|
||||
<entry><structfield>database</structfield></entry>
|
||||
<entry><type>name</type></entry>
|
||||
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.datname</literal></entry>
|
||||
<entry>
|
||||
Name of the database in which the transaction was executed
|
||||
</entry>
|
||||
</row>
|
||||
</tbody>
|
||||
</tgroup>
|
||||
</table>
|
||||
|
||||
<para>
|
||||
When the <structname>pg_prepared_xacts</structname> view is accessed, the
|
||||
internal transaction manager data structures are momentarily locked, and
|
||||
a copy is made for the view to display. This ensures that the
|
||||
view produces a consistent set of results, while not blocking
|
||||
normal operations longer than necessary. Nonetheless
|
||||
there could be some impact on database performance if this view is
|
||||
read often.
|
||||
</para>
|
||||
|
||||
</sect1>
|
||||
|
||||
<sect1 id="view-pg-rules">
|
||||
<title><structname>pg_rules</structname></title>
|
||||
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
<!--
|
||||
$PostgreSQL: pgsql/doc/src/sgml/ref/allfiles.sgml,v 1.62 2004/08/21 16:16:04 tgl Exp $
|
||||
$PostgreSQL: pgsql/doc/src/sgml/ref/allfiles.sgml,v 1.63 2005/06/17 22:32:42 tgl Exp $
|
||||
PostgreSQL documentation
|
||||
Complete list of usable sgml source files in this directory.
|
||||
-->
|
||||
@ -30,6 +30,7 @@ Complete list of usable sgml source files in this directory.
|
||||
<!entity cluster system "cluster.sgml">
|
||||
<!entity commentOn system "comment.sgml">
|
||||
<!entity commit system "commit.sgml">
|
||||
<!entity commitPrepared system "commit_prepared.sgml">
|
||||
<!entity copyTable system "copy.sgml">
|
||||
<!entity createAggregate system "create_aggregate.sgml">
|
||||
<!entity createCast system "create_cast.sgml">
|
||||
@ -88,11 +89,13 @@ Complete list of usable sgml source files in this directory.
|
||||
<!entity move system "move.sgml">
|
||||
<!entity notify system "notify.sgml">
|
||||
<!entity prepare system "prepare.sgml">
|
||||
<!entity prepareTransaction system "prepare_transaction.sgml">
|
||||
<!entity reindex system "reindex.sgml">
|
||||
<!entity releaseSavepoint system "release_savepoint.sgml">
|
||||
<!entity reset system "reset.sgml">
|
||||
<!entity revoke system "revoke.sgml">
|
||||
<!entity rollback system "rollback.sgml">
|
||||
<!entity rollbackPrepared system "rollback_prepared.sgml">
|
||||
<!entity rollbackTo system "rollback_to.sgml">
|
||||
<!entity savepoint system "savepoint.sgml">
|
||||
<!entity select system "select.sgml">
|
||||
|
||||
111
doc/src/sgml/ref/commit_prepared.sgml
Normal file
111
doc/src/sgml/ref/commit_prepared.sgml
Normal file
@ -0,0 +1,111 @@
|
||||
<!--
|
||||
$PostgreSQL: pgsql/doc/src/sgml/ref/commit_prepared.sgml,v 1.1 2005/06/17 22:32:42 tgl Exp $
|
||||
PostgreSQL documentation
|
||||
-->
|
||||
|
||||
<refentry id="SQL-COMMIT-PREPARED">
|
||||
<refmeta>
|
||||
<refentrytitle id="sql-commit-prepared-title">COMMIT PREPARED</refentrytitle>
|
||||
<refmiscinfo>SQL - Language Statements</refmiscinfo>
|
||||
</refmeta>
|
||||
|
||||
<refnamediv>
|
||||
<refname>COMMIT PREPARED</refname>
|
||||
<refpurpose>commit a transaction that was earlier prepared for two-phase commit</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<indexterm zone="sql-commit-prepared">
|
||||
<primary>COMMIT PREPARED</primary>
|
||||
</indexterm>
|
||||
|
||||
<refsynopsisdiv>
|
||||
<synopsis>
|
||||
COMMIT PREPARED <replaceable class="PARAMETER">transaction_id</replaceable>
|
||||
</synopsis>
|
||||
</refsynopsisdiv>
|
||||
|
||||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para>
|
||||
<command>COMMIT PREPARED</command> commits a transaction that is in
|
||||
prepared state.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Parameters</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><replaceable class="PARAMETER">transaction_id</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The transaction identifier of the transaction that is to be
|
||||
committed.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Notes</title>
|
||||
|
||||
<para>
|
||||
To commit a prepared transaction, you must be either the same user that
|
||||
executed the transaction originally, or a superuser. But you do not
|
||||
have to be in the same session that executed the transaction.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
This command cannot be executed inside a transaction block. The prepared
|
||||
transaction is committed immediately.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
All currently available prepared transactions are listed in the
|
||||
<structname>pg_prepared_xacts</> system view.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1 id="sql-commit-prepared-examples">
|
||||
<title id="sql-commit-prepared-examples-title">Examples</title>
|
||||
<para>
|
||||
Commit the transaction identified by the transaction
|
||||
identifier <literal>foobar</>:
|
||||
|
||||
<programlisting>
|
||||
COMMIT PREPARED 'foobar';
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>See Also</title>
|
||||
|
||||
<simplelist type="inline">
|
||||
<member><xref linkend="sql-prepare-transaction" endterm="sql-prepare-transaction-title"></member>
|
||||
<member><xref linkend="sql-rollback-prepared" endterm="sql-rollback-prepared-title"></member>
|
||||
</simplelist>
|
||||
</refsect1>
|
||||
|
||||
</refentry>
|
||||
|
||||
<!-- Keep this comment at the end of the file
|
||||
Local variables:
|
||||
mode: sgml
|
||||
sgml-omittag:nil
|
||||
sgml-shorttag:t
|
||||
sgml-minimize-attributes:nil
|
||||
sgml-always-quote-attributes:t
|
||||
sgml-indent-step:1
|
||||
sgml-indent-data:t
|
||||
sgml-parent-document:nil
|
||||
sgml-default-dtd-file:"../reference.ced"
|
||||
sgml-exposed-tags:nil
|
||||
sgml-local-catalogs:"/usr/lib/sgml/catalog"
|
||||
sgml-local-ecat-files:nil
|
||||
End:
|
||||
-->
|
||||
160
doc/src/sgml/ref/prepare_transaction.sgml
Normal file
160
doc/src/sgml/ref/prepare_transaction.sgml
Normal file
@ -0,0 +1,160 @@
|
||||
<!--
|
||||
$PostgreSQL: pgsql/doc/src/sgml/ref/prepare_transaction.sgml,v 1.1 2005/06/17 22:32:42 tgl Exp $
|
||||
PostgreSQL documentation
|
||||
-->
|
||||
|
||||
<refentry id="SQL-PREPARE-TRANSACTION">
|
||||
<refmeta>
|
||||
<refentrytitle id="sql-prepare-transaction-title">PREPARE TRANSACTION</refentrytitle>
|
||||
<refmiscinfo>SQL - Language Statements</refmiscinfo>
|
||||
</refmeta>
|
||||
|
||||
<refnamediv>
|
||||
<refname>PREPARE TRANSACTION</refname>
|
||||
<refpurpose>prepare the current transaction for two-phase commit</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<indexterm zone="sql-prepare-transaction">
|
||||
<primary>PREPARE TRANSACTION</primary>
|
||||
</indexterm>
|
||||
|
||||
<refsynopsisdiv>
|
||||
<synopsis>
|
||||
PREPARE TRANSACTION <replaceable class="PARAMETER">transaction_id</replaceable>
|
||||
</synopsis>
|
||||
</refsynopsisdiv>
|
||||
|
||||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para>
|
||||
<command>PREPARE TRANSACTION</command> prepares the current transaction
|
||||
for two-phase commit. After this command, the transaction is no longer
|
||||
associated with the current session; instead, its state is fully stored on
|
||||
disk, and there is a very high probability that it can be committed
|
||||
successfully, even if a database crash occurs before the commit is
|
||||
requested.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Once prepared, a transaction can later be committed or rolled
|
||||
back with <command>COMMIT PREPARED</command> or
|
||||
<command>ROLLBACK PREPARED</command>, respectively. Those commands
|
||||
can be issued from any session, not only the one that executed the
|
||||
original transaction.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
From the point of view of the issuing session, <command>PREPARE
|
||||
TRANSACTION</command> is not unlike a <command>ROLLBACK</> command:
|
||||
after executing it, there is no active current transaction, and the
|
||||
effects of the prepared transaction are no longer visible. (The effects
|
||||
will become visible again if the transaction is committed.)
|
||||
</para>
|
||||
|
||||
<para>
|
||||
If the <command>PREPARE TRANSACTION</command> command fails for any
|
||||
reason, it becomes a <command>ROLLBACK</>: the current transaction
|
||||
is canceled.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Parameters</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><replaceable class="PARAMETER">transaction_id</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
An arbitrary identifier that later identifies this transaction for
|
||||
<command>COMMIT PREPARED</> or <command>ROLLBACK PREPARED</>.
|
||||
The identifier must be written as a string literal, and must be
|
||||
less than 200 bytes long. It must not be the same as the identifier
|
||||
used for any currently prepared transaction.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Notes</title>
|
||||
|
||||
<para>
|
||||
This command must be used inside a transaction block. Use
|
||||
<command>BEGIN</command> to start one.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
It is not currently allowed to <command>PREPARE</> a transaction that
|
||||
has executed any operations involving temporary tables nor
|
||||
created any cursors <literal>WITH HOLD</>. Those features are too tightly
|
||||
tied to the current session to be useful in a transaction to be prepared.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
If the transaction modified any run-time parameters with <command>SET</>,
|
||||
those effects persist after <command>PREPARE TRANSACTION</>, and will not
|
||||
be affected by any later <command>COMMIT PREPARED</command> or
|
||||
<command>ROLLBACK PREPARED</command>. Thus, in this one respect
|
||||
<command>PREPARE TRANSACTION</> acts more like <command>COMMIT</> than
|
||||
<command>ROLLBACK</>.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
All currently available prepared transactions are listed in the
|
||||
<structname>pg_prepared_xacts</> system view.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
From a performance standpoint, it is unwise to leave transactions in
|
||||
the prepared state for a long time: this will for instance interfere with
|
||||
the ability of <command>VACUUM</> to reclaim storage. Keep in mind also
|
||||
that the transaction continues to hold whatever locks it held.
|
||||
The intended
|
||||
usage of the feature is that a prepared transaction will normally be
|
||||
committed or rolled back as soon as an external transaction manager
|
||||
has verified that other databases are also prepared to commit.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1 id="sql-prepare-transaction-examples">
|
||||
<title id="sql-prepare-transaction-examples-title">Examples</title>
|
||||
<para>
|
||||
Prepare the current transaction for two-phase commit, using
|
||||
<literal>foobar</> as the transaction identifier:
|
||||
|
||||
<programlisting>
|
||||
PREPARE TRANSACTION 'foobar';
|
||||
</programlisting>
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>See Also</title>
|
||||
|
||||
<simplelist type="inline">
|
||||
<member><xref linkend="sql-commit-prepared" endterm="sql-commit-prepared-title"></member>
|
||||
<member><xref linkend="sql-rollback-prepared" endterm="sql-rollback-prepared-title"></member>
|
||||
</simplelist>
|
||||
</refsect1>
|
||||
|
||||
</refentry>
|
||||
|
||||
<!-- Keep this comment at the end of the file
|
||||
Local variables:
|
||||
mode: sgml
|
||||
sgml-omittag:nil
|
||||
sgml-shorttag:t
|
||||
sgml-minimize-attributes:nil
|
||||
sgml-always-quote-attributes:t
|
||||
sgml-indent-step:1
|
||||
sgml-indent-data:t
|
||||
sgml-parent-document:nil
|
||||
sgml-default-dtd-file:"../reference.ced"
|
||||
sgml-exposed-tags:nil
|
||||
sgml-local-catalogs:"/usr/lib/sgml/catalog"
|
||||
sgml-local-ecat-files:nil
|
||||
End:
|
||||
-->
|
||||
111
doc/src/sgml/ref/rollback_prepared.sgml
Normal file
111
doc/src/sgml/ref/rollback_prepared.sgml
Normal file
@ -0,0 +1,111 @@
|
||||
<!--
|
||||
$PostgreSQL: pgsql/doc/src/sgml/ref/rollback_prepared.sgml,v 1.1 2005/06/17 22:32:42 tgl Exp $
|
||||
PostgreSQL documentation
|
||||
-->
|
||||
|
||||
<refentry id="SQL-ROLLBACK-PREPARED">
|
||||
<refmeta>
|
||||
<refentrytitle id="sql-rollback-prepared-title">ROLLBACK PREPARED</refentrytitle>
|
||||
<refmiscinfo>SQL - Language Statements</refmiscinfo>
|
||||
</refmeta>
|
||||
|
||||
<refnamediv>
|
||||
<refname>ROLLBACK PREPARED</refname>
|
||||
<refpurpose>cancel a transaction that was earlier prepared for two-phase commit</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<indexterm zone="sql-rollback-prepared">
|
||||
<primary>ROLLBACK PREPARED</primary>
|
||||
</indexterm>
|
||||
|
||||
<refsynopsisdiv>
|
||||
<synopsis>
|
||||
ROLLBACK PREPARED <replaceable class="PARAMETER">transaction_id</replaceable>
|
||||
</synopsis>
|
||||
</refsynopsisdiv>
|
||||
|
||||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para>
|
||||
<command>ROLLBACK PREPARED</command> rolls back a transaction that is in
|
||||
prepared state.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Parameters</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><replaceable class="PARAMETER">transaction_id</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The transaction identifier of the transaction that is to be
|
||||
rolled back.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Notes</title>
|
||||
|
||||
<para>
|
||||
To roll back a prepared transaction, you must be either the same user that
|
||||
executed the transaction originally, or a superuser. But you do not
|
||||
have to be in the same session that executed the transaction.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
This command cannot be executed inside a transaction block. The prepared
|
||||
transaction is rolled back immediately.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
All currently available prepared transactions are listed in the
|
||||
<structname>pg_prepared_xacts</> system view.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1 id="sql-rollback-prepared-examples">
|
||||
<title id="sql-rollback-prepared-examples-title">Examples</title>
|
||||
<para>
|
||||
Roll back the transaction identified by the transaction
|
||||
identifier <literal>foobar</>:
|
||||
|
||||
<programlisting>
|
||||
ROLLBACK PREPARED 'foobar';
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>See Also</title>
|
||||
|
||||
<simplelist type="inline">
|
||||
<member><xref linkend="sql-prepare-transaction" endterm="sql-prepare-transaction-title"></member>
|
||||
<member><xref linkend="sql-commit-prepared" endterm="sql-commit-prepared-title"></member>
|
||||
</simplelist>
|
||||
</refsect1>
|
||||
|
||||
</refentry>
|
||||
|
||||
<!-- Keep this comment at the end of the file
|
||||
Local variables:
|
||||
mode: sgml
|
||||
sgml-omittag:nil
|
||||
sgml-shorttag:t
|
||||
sgml-minimize-attributes:nil
|
||||
sgml-always-quote-attributes:t
|
||||
sgml-indent-step:1
|
||||
sgml-indent-data:t
|
||||
sgml-parent-document:nil
|
||||
sgml-default-dtd-file:"../reference.ced"
|
||||
sgml-exposed-tags:nil
|
||||
sgml-local-catalogs:"/usr/lib/sgml/catalog"
|
||||
sgml-local-ecat-files:nil
|
||||
End:
|
||||
-->
|
||||
@ -1,5 +1,5 @@
|
||||
<!-- reference.sgml
|
||||
$PostgreSQL: pgsql/doc/src/sgml/reference.sgml,v 1.52 2004/08/21 16:16:03 tgl Exp $
|
||||
$PostgreSQL: pgsql/doc/src/sgml/reference.sgml,v 1.53 2005/06/17 22:32:42 tgl Exp $
|
||||
|
||||
PostgreSQL Reference Manual
|
||||
-->
|
||||
@ -62,6 +62,7 @@ PostgreSQL Reference Manual
|
||||
&cluster;
|
||||
&commentOn;
|
||||
&commit;
|
||||
&commitPrepared;
|
||||
©Table;
|
||||
&createAggregate;
|
||||
&createCast;
|
||||
@ -120,11 +121,13 @@ PostgreSQL Reference Manual
|
||||
&move;
|
||||
¬ify;
|
||||
&prepare;
|
||||
&prepareTransaction;
|
||||
&reindex;
|
||||
&releaseSavepoint;
|
||||
&reset;
|
||||
&revoke;
|
||||
&rollback;
|
||||
&rollbackPrepared;
|
||||
&rollbackTo;
|
||||
&savepoint;
|
||||
&select;
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
<!--
|
||||
$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.328 2005/06/17 13:12:01 momjian Exp $
|
||||
$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.329 2005/06/17 22:32:42 tgl Exp $
|
||||
-->
|
||||
|
||||
<chapter Id="runtime">
|
||||
@ -956,7 +956,7 @@ SET ENABLE_SEQSCAN TO OFF;
|
||||
<para>
|
||||
Sets the location of the Kerberos server key file. See
|
||||
<xref linkend="kerberos-auth"> for details. This parameter
|
||||
can only be set at server start.
|
||||
can only be set at server start.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1113,6 +1113,33 @@ SET ENABLE_SEQSCAN TO OFF;
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry id="guc-max-prepared-transactions" xreflabel="max_prepared_transactions">
|
||||
<term><varname>max_prepared_transactions</varname> (<type>integer</type>)</term>
|
||||
<indexterm>
|
||||
<primary><varname>max_prepared_transactions</> configuration parameter</primary>
|
||||
</indexterm>
|
||||
<listitem>
|
||||
<para>
|
||||
Sets the maximum number of transactions that can be in the
|
||||
<quote>prepared</> state simultaneously (see <xref
|
||||
linkend="sql-prepare-transaction"
|
||||
endterm="sql-prepare-transaction-title">).
|
||||
Setting this parameter to zero disables the prepared-transaction
|
||||
feature.
|
||||
The default is 50.
|
||||
This option can only be set at server start.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Increasing this parameter may cause <productname>PostgreSQL</>
|
||||
to request more <systemitem class="osname">System V</> shared
|
||||
memory than your operating system's default configuration
|
||||
allows. See <xref linkend="sysvipc"> for information on how to
|
||||
adjust those parameters, if necessary.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry id="guc-work-mem" xreflabel="work_mem">
|
||||
<term><varname>work_mem</varname> (<type>integer</type>)</term>
|
||||
<indexterm>
|
||||
|
||||
Reference in New Issue
Block a user