<chapter id="backup">

<title>Backup and Restore</title>

If recovery fails for an external reason, such as a system crash or

the WAL archive has become inaccessible, then the recovery can be

simply restarted and it will restart almost from where it failed.

file at the first safely usable checkpoint record found after

<varname>checkpoint_timeout</> seconds.

</para>

<para>

If we take a backup of the server files whilst a recovery is in progress,

That backup now has many of the changes from previous WAL archive files,

so this version is now an updated version of the original base backup.

If we need to recover, it will be faster to recover from the

<para>

An external program can call <function>pg_xlogfile_name_offset()</>

the latest WAL pointer. If the external program regularly polls

the server it can find out how far forward the pointer has

moved. It can then access the WAL file directly and copy those

<!--

Documentation of the system catalogs, directed toward PostgreSQL developers

-->

<entry><structfield>amclusterable</structfield></entry>

<entry><type>bool</type></entry>

<entry></entry>

</row>

<row>

<entry><structfield>amoptions</structfield></entry>

<entry><type>regproc</type></entry>

<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>

</row>

</tbody>

<entry><structfield>vac_scale_factor</structfield></entry>

<entry><type>float4</type></entry>

<entry></entry>

<structfield>vac_base_thresh</></entry>

</row>

<entry><structfield>anl_scale_factor</structfield></entry>

<entry><type>float4</type></entry>

<entry></entry>

<structfield>anl_base_thresh</></entry>

</row>

operation. All rows inserted or deleted by transaction IDs before this one

have been marked as known good or deleted. This

is used to determine when commit-log space can be recycled.

determined by scanning <structname>pg_class</>.<structfield>relvacuumxid</>.

</entry>

</row>

relabeled with a permanent (<quote>frozen</>) transaction ID in this

database. This is useful to check whether a database must be

vacuumed soon to avoid transaction ID wrap-around problems.

determined by scanning <structname>pg_class</>.<structfield>relminxid</>.

</entry>

</row>

<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>

<entry>

An array with the data types of the function arguments. This includes

the call signature of the function.

</entry>

</row>

<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>

<entry>

An array with the data types of the function arguments. This includes

arguments are IN arguments, this field will be null.

Note that subscripting is 1-based, whereas for historical reasons

<structfield>proargtypes</> is subscripted from 0.

<entry></entry>

<entry>

An array with the modes of the function arguments, encoded as

Note that subscripts correspond to positions of

<structfield>proallargtypes</> not <structfield>proargtypes</>.

</entry>

<para>

Advisory locks can be acquired on keys consisting of either a single

high-order half in the <structfield>classid</> column, its low-order half

in the <structfield>objid</> column, and <structfield>objsubid</> equal

to 1. Integer keys are displayed with the first key in the

<chapter id="client-authentication">

<title>Client Authentication</title>

</para>

<para>

The server will bind to the distinguished name specified as

If <replaceable>prefix</> and <replaceable>suffix</> is

before the bind. Typically, the prefix parameter is used to specify

<replaceable>cn=</>, or <replaceable>DOMAIN\</> in an Active

Directory environment.

<chapter Id="runtime-config">

<title>Server Configuration</title>

<programlisting>

include 'filename'

</programlisting>

the directory containing the referencing configuration file.

Inclusions can be nested.

</para>

<para>

Specifies the main server configuration file

(customarily called <filename>postgresql.conf</>).

</para>

</listitem>

</varlistentry>

<para>

If you wish to keep the configuration files elsewhere than the

command-line option or <envar>PGDATA</envar> environment variable

must point to the directory containing the configuration files,

and the <varname>data_directory</> parameter must be set in

or power failure. The risks are similar to turning off

<varname>fsync</>, though smaller. It may be safe to turn off

this parameter if you have hardware (such as a battery-backed disk

</para>

<para>

<listitem>

<para>

This controls whether the array input parser recognizes

By default, this is <literal>on</>, allowing array values containing

treat <literal>NULL</> as specifying a normal array element with

the string value <quote>NULL</>. For backwards compatibility with

applications that require the old behavior, this variable can be

turned <literal>off</>.

</para>

<para>

even when this variable is <literal>off</>.

</para>

</listitem>

<appendix id="cvs">

<appendixinfo>

<para>

If you have a fast link to the Internet, you may not need

<option>-z3</option>, which instructs

on a modem-speed link, it's a very substantial win.

</para>

</note>

update -d -P

</programlisting>

to say

<programlisting>

cvs update

<para>

When you tag more than one file with the same tag you can think

revision number</quote>. Say we have 5 files with the following revisions:

<programlisting>

A major advantage to using

<productname>CVSup</productname> is that it can reliably

replicate the <emphasis>entire</emphasis> CVS repository on your local system,

and <option>diff</option>. Other advantages include fast synchronization to

the <productname>PostgreSQL</productname> server due to an efficient

streaming transfer protocol which only sends the changes since the last update.

</para>

<para>

the <productname>PostgreSQL</>

<ulink url="ftp://ftp.postgresql.org/pub/CVSup/README.cvsup">

ftp site</ulink>

<step>

<para>

If there is a directory structure in the tar file, then unpack

the appropriate location as above.

</para>

</step>

<step>

<para>

<programlisting>

# rpm -Uvh pm3*.rpm

<chapter id="datatype">

<title id="datatype-title">Data Types</title>

</indexterm>

<para>

capability, but a variety of features supported by a database

system. These capabilities include storage, import/export,

validation, indexing, efficiency of modification, searching,

indexes to index specific <acronym>XML</> fields. To index the

full contents of <acronym>XML</> documents, the full-text indexing

tool <filename>/contrib/tsearch2</> can be used. Of course,

<filename>/contrib/xml2</> checks should be added to queries.

</para>

</listitem>

<listitem>

<para>

Stylesheet Language Transformation).

</para>

</listitem>

<chapter id="ddl">

<title>Data Definition</title>

However, the need to

recreate the view adds an extra step to adding and dropping

</para>

</sect2>

Constraint exclusion only works when the query's <literal>WHERE</>

clause contains constants. A parameterized query will not be

optimized, since the planner cannot know what partitions the

<quote>stable</> functions such as <function>CURRENT_DATE</function>

must be avoided.

</para>

</listitem>

<listitem>

<para>

constraints, as the planner will currently fail to prove such

conditions false. For example, the following constraint

will work if <varname>x</varname> is an <type>integer</type>

The problem is not limited to the <type>bigint</type> data type

&mdash; it can occur whenever the default data type of the

constant does not match the data type of the column to which it

queries are usually OK, just not in the <literal>CHECK</> conditions.

</para>

</listitem>

<appendix id="docguide">

<title>Documentation</title>

<envar>SGML_CATALOG_FILES</envar> to point to the file

whenever you use <application>jade</application> later on.

(This method is also an option if OpenJade is already

locally.)

</para>

</step>