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Attached patch takes a swing at improving the autovacuum wording in

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maintenance.sgml.

Robert Treat

[ Also fix create domain markup.]
This commit is contained in:
Bruce Momjian 2005-09-23 02:01:35 +00:00
parent 0135cd88bd
commit 18ea8ae531
2 changed files with 23 additions and 16 deletions
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25
doc/src/sgml/maintenance.sgml
View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.47 2005/09/16 03:12:32 alvherre Exp $
$PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.48 2005/09/23 02:01:34 momjian Exp $
-->
<chapter id="maintenance">
@ -180,7 +180,8 @@ $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.47 2005/09/16 03:12:32 alvh
rate of data modification <command>VACUUM</command> busy tables as
often as once every few minutes.) If you have multiple databases
in a cluster, don't forget to <command>VACUUM</command> each one;
the program <filename>vacuumdb</> may be helpful.
the program <xref linkend="app-vacuumdb" endterm="app-vacuumdb-title">
may be helpful.
</para>
<para>
@ -466,7 +467,7 @@ HINT: Stop the postmaster and use a standalone backend to VACUUM in "mydb".
<para>
Beginning in <productname>PostgreSQL </productname> 8.1, there is a
separate optional server process called the <firstterm>autovacuum
daemon</firstterm>, whose purpose is to automate the issuance of
daemon</firstterm>, whose purpose is to automate the execution of
<command>VACUUM</command> and <command>ANALYZE </command> commands.
When enabled, the autovacuum daemon runs periodically and checks for
tables that have had a large number of inserted, updated or deleted
@ -521,29 +522,29 @@ vacuum threshold = vacuum base threshold + vacuum scale factor * number of tuple
<para>
Note that if any of the values in <structname>pg_autovacuum</structname>
is set to a negative number, or if a tuple is not present at all in
are set to a negative number, or if a tuple is not present at all in
<structname>pg_autovacuum</structname> for any particular table, the
equivalent value from <filename>postgresql.conf</filename> is used.
</para>
<para>
Besides the base threshold values and scale factors, there are three
parameters that can be set for each table in <structname>pg_autovacuum</structname>:
the vacuum cost delay
parameters that can be set for each table in <structname>pg_autovacuum</structname>.
The first parameter, <structname>pg_autovacuum</>.<structfield>enabled</>,
can be used to instruct the autovacuum daemon to skip any particular table
by setting it to <literal>false</literal>.
The other two, the vacuum cost delay
(<structname>pg_autovacuum</structname>.<structfield>vac_cost_delay</structfield>)
and the vacuum cost limit
(<structname>pg_autovacuum</structname>.<structfield>vac_cost_limit</structfield>).
They are used to set table-specific values for the
(<structname>pg_autovacuum</structname>.<structfield>vac_cost_limit</structfield>),
are used to set table-specific values for the
<xref linkend="runtime-config-resource-vacuum-cost" endterm="runtime-config-resource-vacuum-cost-title">
feature. The above note about negative values also applies here, but
also note that if the <filename>postgresql.conf</filename> variables
<varname>autovacuum_vacuum_cost_limit</varname> and
<varname>autovacuum_vacuum_cost_delay</varname> are also set to negative
values, the <varname>vacuum_cost_limit</varname> and
values, the global <varname>vacuum_cost_limit</varname> and
<varname>vacuum_cost_delay</varname> values will be used instead.
The other parameter, <structname>pg_autovacuum</>.<structfield>enabled</>,
can be used to instruct the autovacuum daemon to skip any particular table
by setting it to <literal>false</literal>.
</para>
<note>

14
doc/src/sgml/ref/create_domain.sgml
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@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/create_domain.sgml,v 1.23 2005/09/22 23:56:46 momjian Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/create_domain.sgml,v 1.24 2005/09/23 02:01:35 momjian Exp $
PostgreSQL documentation
-->
@ -52,10 +52,16 @@ where <replaceable class="PARAMETER">constraint</replaceable> is:
into a single location for maintenance. For example, an email address
column may be used in several tables, all with the same properties.
Define a domain and use that rather than setting up each table's
constraints individually. <note>Keep in mind also that declaring a
function result value as a domain is pretty dangerous, because none of
the PLs enforce domain constraints on their results.</note>
constraints individually.
</para>
<note>
<para>
Keep in mind also that declaring a function result value as a domain
is pretty dangerous, because none of the PLs enforce domain constraints
on their results.
</para>
</note>
</refsect1>
<refsect1>