2000-03-31 05:27:42 +02:00
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$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.57 2001/03/16 05:44:33 tgl Exp $
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2000-03-31 05:27:42 +02:00
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2000-06-18 23:24:54 +02:00
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<Chapter Id="runtime">
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<Title>Server Runtime Environment</Title>
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<Para>
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This chapter discusses how to set up and run the database server
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and the interactions with the operating system.
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</para>
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<sect1 id="postgres-user">
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<title>The Postgres user account</title>
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<para>
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As with any other server daemon that is connected to the world at
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large, it is advisable to run Postgres under a separate user
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account. This user account should only own the data itself that is
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being managed by the server, and should not be shared with other
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daemons. (Thus, using the user <quote>nobody</quote> is a bad
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idea.) It is not advisable to install the executables as owned by
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this user account because that runs the risk of user-defined
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functions gone astray or any other exploits compromising the
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executable programs.
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</para>
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1999-05-20 07:39:29 +02:00
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2000-06-18 23:24:54 +02:00
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<para>
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To add a user account to your system, look for a command
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<command>useradd</command> or <command>adduser</command>. The user
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name <quote>postgres</quote> is often used but by no means
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required.
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</para>
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</sect1>
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<sect1 id="creating-cluster">
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<title>Creating a database cluster</title>
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<para>
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Before you can do anything, you must initialize a database storage
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area on disk. We call this a <firstterm>database
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cluster</firstterm>. (<acronym>SQL</acronym> speaks of a catalog
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cluster instead.) A database cluster is a collection of databases
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that will be accessible through a single instance of a running
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database server. After initialization, a database cluster will
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contain one database named <literal>template1</literal>. As the
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name suggests, this will be used as a template for any subsequently
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created database; it should not be used for actual work.
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1999-05-20 07:39:29 +02:00
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</para>
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2000-06-18 23:24:54 +02:00
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<para>
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In file system terms, a database cluster will be a single directory
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under which all data will be stored. We call this the
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<firstterm>data directory</firstterm> or <firstterm>data
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area</firstterm>. It is completely up to you where you choose to
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store your data, there is no default, although locations such as
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<filename>/usr/local/pgsql/data</filename> or
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<filename>/var/lib/pgsql/data</filename> are popular. To initialize
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a database cluster, use the command <command>initdb</command>,
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which is installed with <productname>PostgreSQL</productname>. The
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desired file system location of your database system is indicated
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by the <option>-D</option> option, for example
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<screen>
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> <userinput>initdb -D /usr/local/pgsql/data</userinput>
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</screen>
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Note that you must execute this command while being logged in to
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the Postgres user account, which is described in the previous
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section.
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</para>
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1999-05-20 07:39:29 +02:00
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2000-06-18 23:24:54 +02:00
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<tip>
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1999-05-20 07:39:29 +02:00
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<para>
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As an alternative to the <option>-D</option> option, you can set
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the environment variable <envar>PGDATA</envar>.
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1999-05-20 07:39:29 +02:00
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</para>
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2000-06-18 23:24:54 +02:00
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</tip>
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<para>
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<command>initdb</command> will attempt to create the directory you
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specify if it does not already exist. It is likely that it won't
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have the permission to do so (if you followed our advice and
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2000-11-25 21:33:54 +01:00
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created an unprivileged account). In that case you should create the
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directory yourself (as root) and transfer ownership of it to the
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Postgres user account. Here is how this might work:
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<screen>
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root# <userinput>mkdir /usr/local/pgsql/data</userinput>
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root# <userinput>chown postgres /usr/local/pgsql/data</userinput>
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root# <userinput>su postgres</userinput>
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postgres> <userinput>initdb -D /usr/local/pgsql/data</userinput>
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</screen>
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</para>
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1999-05-20 07:39:29 +02:00
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2000-06-18 23:24:54 +02:00
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<para>
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<command>initdb</command> will refuse to run if the data directory
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looks like it belongs to an already initialized installation.
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</para>
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<para>
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Because the data directory contains all the data stored in the
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database it is essential that it be well secured from unauthorized
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access. <command>initdb</command> therefore revokes access
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permissions from everyone but the Postgres user account.
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</para>
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2000-11-25 21:33:54 +01:00
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<para>
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One surprise you might encounter while running <command>initdb</command> is
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a notice similar to this one:
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<screen>
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NOTICE: Initializing database with en_US collation order.
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This locale setting will prevent use of index optimization for
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LIKE and regexp searches. If you are concerned about speed of
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such queries, you may wish to set LC_COLLATE to "C" and
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re-initdb. For more information see the Administrator's Guide.
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</screen>
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This notice is intended to warn you that the currently selected locale
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will cause indexes to be sorted in an order that prevents them from
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being used for LIKE and regular-expression searches. If you need
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good performance of such searches, you should set your current locale
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to "C" and re-run <command>initdb</command>. On most systems, setting the
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current locale is done by changing the value of the environment variable
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<literal>LC_ALL</literal> or <literal>LANG</literal>. The sort order used
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within a particular database cluster is set by <command>initdb</command>
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and cannot be changed later, short of dumping all data, re-initdb,
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reload data. So it's important to make this choice correctly now.
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</para>
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2000-06-18 23:24:54 +02:00
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</sect1>
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<sect1 id="postmaster-start">
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<title>Starting the database server</title>
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<para>
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Before anyone can access the database you must start the database
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server. The database server is called
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<firstterm>postmaster</firstterm>.
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The postmaster must know where to find the data it is supposed
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to work on. This is done with the <option>-D</option> option. Thus,
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the simplest way to start the server is, for example,
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<screen>
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> <userinput>postmaster -D /usr/local/pgsql/data</userinput>
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</screen>
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which will leave the server running in the foreground. This must
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again be done while logged in to the Postgres user account. Without
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a <option>-D</option>, the server will try to use the data
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directory in the environment variable <envar>PGDATA</envar>; if
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neither of these works it will fail.
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</para>
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<para>
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To start the <application>postmaster</application> in the
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background, use the usual shell syntax:
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<screen>
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2000-10-19 06:53:41 +02:00
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> <userinput>postmaster -D /usr/local/pgsql/data > logfile 2>&1 &</userinput>
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</screen>
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It is an extremely good idea to keep the server output around
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somewhere, as indicated here. It will help both for auditing
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purposes and to diagnose problems.
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</para>
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<para>
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The postmaster also takes a number of other command line options.
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For more information see the reference page and below under runtime
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configuration. In particular, in order for the postmaster to accept
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TCP/IP connections (rather than just Unix domain socket ones), you
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must also specify the <option>-i</option> option.
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</para>
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2001-02-10 01:50:18 +01:00
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<para>
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This shells syntax can get tedious quickly. Therefore the shell
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script wrapper <application>pg_ctl</application> is provided that
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encapsulates some of the tasks. E.g.,
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<programlisting>
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pg_ctl start -l logfile
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</programlisting>
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will start the server in the background and put the output into the
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named log file. The <option>-D</option> option has the same
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meaning as when invoking postmaster directly.
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<application>pg_ctl</application> also implements a symmetric
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<quote>stop</quote> operation.
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</para>
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2000-06-18 23:24:54 +02:00
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<para>
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Normally, you will want to start the database server when the
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computer boots up. This is not required; the
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<productname>PostgreSQL</productname> server can be run
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successfully from non-privileged accounts without root
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intervention.
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</para>
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<para>
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Different systems have different conventions for starting up
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daemons at boot time, so you are advised to familiarize yourself
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with them. Many systems have a file
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<filename>/etc/rc.local</filename> or
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<filename>/etc/rc.d/rc.local</filename> which is almost certainly
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2001-02-10 01:50:18 +01:00
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no bad place to put such a command. Whatever you do, the server
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2000-06-18 23:24:54 +02:00
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must be run by the <productname>Postgres</productname> user account
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<emphasis>and not by root</emphasis> or any other user. Therefore
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you probably always want to form your command lines along the lines
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of <literal>su -c '...' postgres</literal>, for example:
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<programlisting>
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2001-02-10 01:50:18 +01:00
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su -c 'pg_ctl -D /usr/local/pgsql/data -l serverlog' postgres
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2000-06-18 23:24:54 +02:00
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</programlisting>
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</para>
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<para>
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2001-02-10 01:50:18 +01:00
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Here are a few more operating system specific suggestions. (Always
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replace the proper installation directory and the user name you
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chose.)
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2000-06-18 23:24:54 +02:00
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<itemizedlist>
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<listitem>
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<para>
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2001-02-10 01:50:18 +01:00
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For <productname>FreeBSD</productname>, take a look at the file
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<filename>contrib/start-scripts/freebsd</filename> in the
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<productname>PostgreSQL</productname> source distribution.
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</para>
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</listitem>
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<listitem>
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<para>
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On <productname>OpenBSD</productname>, add the following lines
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to the file <filename>/etc/rc.local</filename>:
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2000-06-18 23:24:54 +02:00
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<programlisting>
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2001-02-10 01:50:18 +01:00
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if [ -x /usr/local/pgsql/bin/pg_ctl -a -x /usr/local/pgsql/bin/postmaster ]; then
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su - -c '/usr/local/pgsql/bin/pg_ctl start -l /var/postgresql/log -s' postgres
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echo -n ' postgresql'
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fi
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2000-06-18 23:24:54 +02:00
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</programlisting>
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</para>
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</listitem>
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<listitem>
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<para>
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2001-02-10 01:50:18 +01:00
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On <productname>Linux</productname> systems either add
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2000-06-18 23:24:54 +02:00
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<programlisting>
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2001-02-10 01:50:18 +01:00
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/usr/local/pgsql/bin/pg_ctl start -l logfile -D /usr/local/pgsql/data
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2000-06-18 23:24:54 +02:00
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</programlisting>
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2001-02-10 01:50:18 +01:00
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to <filename>/etc/rc.d/rc.local</filename> or look into the file
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<filename>contrib/start-scripts/linux</filename> in the
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<productname>PostgreSQL</productname> source distribution to
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integrate the start and shutdown into the run level system.
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2000-06-18 23:24:54 +02:00
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</para>
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</listitem>
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<listitem>
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<para>
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2001-02-10 01:50:18 +01:00
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On <productname>NetBSD</productname>, either use the
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<productname>FreeBSD</productname> or
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<productname>Linux</productname> start scripts, depending on
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preference, as an example and place the file at
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<filename>/usr/local/etc/rc.d/postgresql</filename>.
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</para>
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</listitem>
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<listitem>
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<para>
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On <productname>Solaris</productname>, edit the file
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<filename>rc2.d</filename> to contain the following single line:
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<programlisting>
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su - postgres -c "/usr/local/pgsql/bin/pg_ctl start -l logfile -D /usr/local/pgsql/data"
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</programlisting>
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</para>
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</listitem>
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</itemizedlist>
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</para>
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1999-05-20 07:39:29 +02:00
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2000-06-18 23:24:54 +02:00
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<para>
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While the <application>postmaster</application> is running, it's
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PID is in the file <filename>postmaster.pid</filename> in the data
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directory. This is used as in interlock against multiple running
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postmaster on the same data directory and can also be used for
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shutting down the postmaster.
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1999-05-20 07:39:29 +02:00
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</para>
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2000-06-18 23:24:54 +02:00
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<sect2 id="postmaster-start-failures">
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2000-08-29 22:02:09 +02:00
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<title>Server Start-up Failures</title>
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2000-06-18 23:24:54 +02:00
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<para>
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There are several common reasons for the postmaster to fail to
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start up. Check the postmaster's log file, or start it by hand
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(without redirecting standard output or standard error) to see
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what complaint messages appear. Some of the possible error
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messages are reasonably self-explanatory, but here are some that
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are not.
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</para>
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<para>
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<screen>
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FATAL: StreamServerPort: bind() failed: Address already in use
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Is another postmaster already running on that port?
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</screen>
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This usually means just what it suggests: you accidentally
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started a second postmaster on the same port where one is already
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running. However, if the kernel error message is not
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<computeroutput>Address already in use</computeroutput> or some
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variant of that wording, there may be a different problem. For
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example, trying to start a postmaster on a reserved port number
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may draw something like
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<screen>
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> <userinput>postmaster -i -p 666</userinput>
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FATAL: StreamServerPort: bind() failed: Permission denied
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Is another postmaster already running on that port?
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</screen>
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</para>
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<para>
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A message like
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<screen>
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2000-07-22 16:49:01 +02:00
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IpcMemoryCreate: shmget(key=5440001, size=83918612, 01600) failed: Invalid argument
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2000-06-18 23:24:54 +02:00
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FATAL 1: ShmemCreate: cannot create region
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</screen>
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probably means that your kernel's limit on the size of shared
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memory areas is smaller than the buffer area that Postgres is
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trying to create (83918612 bytes in this example). Or it could
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2000-07-22 16:49:01 +02:00
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mean that you don't have System-V-style shared memory support
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2000-06-18 23:24:54 +02:00
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configured into your kernel at all. As a temporary workaround,
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you can try starting the postmaster with a smaller-than-normal
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number of buffers (<option>-B</option> switch). You will
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|
eventually want to reconfigure your kernel to increase the
|
|
|
|
allowed shared memory size, however. You may see this message
|
|
|
|
when trying to start multiple postmasters on the same machine, if
|
|
|
|
their total space requests exceed the kernel limit.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
An error like
|
|
|
|
<screen>
|
2000-07-22 16:49:01 +02:00
|
|
|
IpcSemaphoreCreate: semget(key=5440026, num=16, 01600) failed: No space left on device
|
2000-06-18 23:24:54 +02:00
|
|
|
</screen>
|
|
|
|
does <emphasis>not</emphasis> mean that you've run out of disk
|
2000-07-22 16:49:01 +02:00
|
|
|
space; it means that your kernel's limit on the number of System
|
|
|
|
V semaphores is smaller than the number
|
2000-06-18 23:24:54 +02:00
|
|
|
<productname>Postgres</productname> wants to create. As above,
|
|
|
|
you may be able to work around the problem by starting the
|
|
|
|
postmaster with a reduced number of backend processes
|
|
|
|
(<option>-N</option> switch), but you'll eventually want to
|
|
|
|
increase the kernel limit.
|
|
|
|
</para>
|
2000-07-22 16:49:01 +02:00
|
|
|
|
2000-08-26 21:34:24 +02:00
|
|
|
<para>
|
|
|
|
If you get an <quote>illegal system call</> error, then it is likely that
|
|
|
|
shared memory or semaphores are not supported at all in your kernel. In
|
|
|
|
that case your only option is to re-configure the kernel to turn on these
|
|
|
|
features.
|
|
|
|
</para>
|
|
|
|
|
2000-07-22 16:49:01 +02:00
|
|
|
<para>
|
|
|
|
Details about configuring System V IPC facilities are given in
|
|
|
|
<xref linkend="sysvipc">.
|
|
|
|
</para>
|
2000-06-18 23:24:54 +02:00
|
|
|
</sect2>
|
|
|
|
|
|
|
|
<sect2 id="client-connection-problems">
|
|
|
|
<title>Client Connection Problems</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Although the possible error conditions on the client side are
|
|
|
|
both virtually infinite and application dependent, a few of them
|
|
|
|
might be directly related to how the server was started up.
|
|
|
|
Conditions other than those shown below should be documented with
|
|
|
|
the respective client application.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
<screen>
|
|
|
|
connectDB() -- connect() failed: Connection refused
|
2000-12-01 00:20:51 +01:00
|
|
|
Is the postmaster running (with -i) at 'server.joe.com' and accepting connections on TCP/IP port 5432?
|
2000-06-18 23:24:54 +02:00
|
|
|
</screen>
|
|
|
|
This is the generic <quote>I couldn't find a server to talk
|
|
|
|
to</quote> failure. It looks like the above when TCP/IP
|
|
|
|
communication is attempted. A common mistake is to forget the
|
|
|
|
<option>-i</option> to the postmaster to allow TCP/IP
|
|
|
|
connections.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Alternatively, you'll get this when attempting
|
|
|
|
Unix-socket communication to a local postmaster:
|
|
|
|
<screen>
|
|
|
|
connectDB() -- connect() failed: No such file or directory
|
2000-12-01 00:20:51 +01:00
|
|
|
Is the postmaster running locally and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?
|
2000-06-18 23:24:54 +02:00
|
|
|
</screen>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The last line is useful in verifying that the client is trying to
|
|
|
|
connect where it is supposed to. If there is in fact no
|
|
|
|
postmaster running there, the kernel error message will typically
|
|
|
|
be either <computeroutput>Connection refused</computeroutput> or
|
|
|
|
<computeroutput>No such file or directory</computeroutput>, as
|
|
|
|
illustrated. (It is particularly important to realize that
|
|
|
|
<computeroutput>Connection refused</computeroutput> in this
|
|
|
|
context does <emphasis>not</emphasis> mean that the postmaster
|
|
|
|
got your connection request and rejected it -- that case will
|
|
|
|
produce a different message, as shown in <xref
|
|
|
|
linkend="client-authentication-problems">.) Other error messages
|
|
|
|
such as <computeroutput>Connection timed out</computeroutput> may
|
|
|
|
indicate more fundamental problems, like lack of network
|
|
|
|
connectivity.
|
|
|
|
</para>
|
|
|
|
</sect2>
|
1999-05-20 07:39:29 +02:00
|
|
|
</sect1>
|
|
|
|
|
2000-09-29 22:21:34 +02:00
|
|
|
<sect1 id="runtime-config">
|
2000-06-18 23:24:54 +02:00
|
|
|
<Title>Run-time configuration</Title>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<para>
|
|
|
|
There are a lot of configuration parameters that affect the
|
|
|
|
behavior of the database system in some way or other. Here we
|
|
|
|
describe how to set them and the following subsections will
|
|
|
|
discuss each of them.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
All parameter names are case-insensitive. Every parameter takes a
|
|
|
|
value of one of the four types boolean, integer, floating point,
|
|
|
|
string as described below. Boolean values are
|
|
|
|
<literal>ON</literal>, <literal>OFF</literal>,
|
|
|
|
<literal>TRUE</literal>, <literal>FALSE</literal>,
|
|
|
|
<literal>YES</literal>, <literal>NO</literal>,
|
|
|
|
<literal>1</literal>, <literal>0</literal> (case-insensitive) or
|
|
|
|
any non-ambiguous prefix of these.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<para>
|
|
|
|
One way to set these options is to create a file
|
|
|
|
<filename>postgresql.conf</filename> in the data directory (e.g.,
|
2000-07-18 00:32:44 +02:00
|
|
|
<filename>/usr/local/pgsql/data</filename>). An example of what
|
|
|
|
this file could look like is:
|
2000-06-18 23:24:54 +02:00
|
|
|
<programlisting>
|
|
|
|
# This is a comment
|
|
|
|
log_connections = yes
|
|
|
|
syslog = 2
|
|
|
|
</programlisting>
|
|
|
|
As you see, options are one per line. The equal sign between name
|
|
|
|
and value is optional. White space is insignificant, blank lines
|
|
|
|
are ignored. Hash marks (<quote>#</quote>) introduce comments
|
|
|
|
anywhere.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
The configuration file is reread whenever the postmaster receives
|
|
|
|
a SIGHUP signal. This signal is also propagated to all running
|
|
|
|
backend processes, so that running sessions get the new default.
|
|
|
|
Alternatively, you can send the signal to only one backend process
|
|
|
|
directly.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
A second way to set these configuration parameters is to give them
|
|
|
|
as a command line option to the postmaster, such as
|
|
|
|
<programlisting>
|
2000-11-08 18:57:46 +01:00
|
|
|
postmaster -c log_connections=yes -c syslog=2
|
2000-06-18 23:24:54 +02:00
|
|
|
</programlisting>
|
|
|
|
which would have the same effect as the previous example.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<para>
|
|
|
|
Occasionally it is also useful to give a command line option to
|
|
|
|
one particular backend session only. The environment variable
|
|
|
|
<envar>PGOPTIONS</envar> can be used for this purpose on the
|
|
|
|
client side:
|
|
|
|
<programlisting>
|
2000-11-08 18:57:46 +01:00
|
|
|
env PGOPTIONS='-c geqo=off' psql
|
2000-06-18 23:24:54 +02:00
|
|
|
</programlisting>
|
|
|
|
(This works for any client application, not just
|
|
|
|
<application>psql</application>.) Note that this won't work for
|
|
|
|
options that are necessarily fixed once the server is started,
|
|
|
|
such as the port number.
|
|
|
|
</para>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<para>
|
|
|
|
Finally, some options can be changed in individual SQL sessions
|
|
|
|
with the <command>SET</command> command, for example
|
|
|
|
<screen>
|
|
|
|
=> <userinput>SET ENABLE_SEQSCAN TO OFF;</userinput>
|
|
|
|
</screen>
|
|
|
|
See the SQL command language reference for details on the syntax.
|
|
|
|
</para>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<sect2 id="runtime-config-optimizer">
|
|
|
|
<title>Planner and Optimizer Tuning</title>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<para>
|
|
|
|
<variablelist>
|
|
|
|
<varlistentry>
|
|
|
|
<term>CPU_INDEX_TUPLE_COST (<type>floating point</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the query optimizer's estimate of the cost of processing
|
|
|
|
each index tuple during an index scan. This is measured as a
|
|
|
|
fraction of the cost of a sequential page fetch.
|
|
|
|
</para>
|
1999-05-20 07:39:29 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
|
1999-05-20 07:39:29 +02:00
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>CPU_OPERATOR_COST (<type>floating point</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Sets the optimizer's estimate of the cost of processing each
|
|
|
|
operator in a WHERE clause. This is measured as a fraction of
|
|
|
|
the cost of a sequential page fetch.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
2000-06-18 23:24:54 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>CPU_TUPLE_COST (<type>floating point</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the query optimizer's estimate of the cost of processing
|
|
|
|
each tuple during a query. This is measured as a fraction of
|
|
|
|
the cost of a sequential page fetch.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>EFFECTIVE_CACHE_SIZE (<type>floating point</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the optimizer's assumption about the effective size of
|
|
|
|
the disk cache (that is, the portion of the kernel's disk
|
|
|
|
cache that will be used for
|
|
|
|
<productname>Postgres</productname> data files). This is
|
|
|
|
measured in disk pages, which are normally 8kB apiece.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<varlistentry>
|
|
|
|
<term>ENABLE_HASHJOIN (<type>boolean</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Enables or disables the query planner's use of hash-join plan
|
|
|
|
types. The default is on. This is mostly useful to debug the
|
|
|
|
query planner.
|
|
|
|
</para>
|
1999-05-20 07:39:29 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>ENABLE_INDEXSCAN (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables the query planner's use of index scan plan
|
|
|
|
types. The default is on. This is mostly useful to debug the
|
|
|
|
query planner.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>ENABLE_MERGEJOIN (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables the query planner's use of merge-join plan
|
|
|
|
types. The default is on. This is mostly useful to debug the
|
|
|
|
query planner.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>ENABLE_NESTLOOP (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables the query planner's use of nested-loop
|
|
|
|
join plans. It's not possible to suppress nested-loop joins
|
|
|
|
entirely, but turning this variable off discourages the
|
|
|
|
planner from using one if there is any other method available.
|
|
|
|
The default is on. This is mostly useful to debug the query
|
|
|
|
planner.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2000-04-23 02:25:06 +02:00
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>ENABLE_SEQSCAN (<type>boolean</type>)</term>
|
2000-04-23 02:25:06 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables the query planner's use of sequential scan
|
|
|
|
plan types. It's not possible to suppress sequential scans
|
|
|
|
entirely, but turning this variable off discourages the
|
|
|
|
planner from using one if there is any other method available.
|
|
|
|
The default is on. This is mostly useful to debug the query
|
|
|
|
planner.
|
2000-04-23 02:25:06 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>ENABLE_SORT (<type>boolean</type>)</term>
|
2000-04-23 02:25:06 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables the query planner's use of explicit sort
|
|
|
|
steps. It's not possible to suppress explicit sorts entirely,
|
|
|
|
but turning this variable off discourages the planner from
|
|
|
|
using one if there is any other method available. The default
|
|
|
|
is on. This is mostly useful to debug the query planner.
|
2000-04-23 02:25:06 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>ENABLE_TIDSCAN (<type>boolean</type>)</term>
|
2000-04-23 02:25:06 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables the query planner's use of TID scan plan
|
|
|
|
types. The default is on. This is mostly useful to debug the
|
|
|
|
query planner.
|
2000-04-23 02:25:06 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
1999-05-20 07:39:29 +02:00
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>GEQO (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Enables or disables genetic query optimization, which is an
|
|
|
|
algorithm that attempts to do query planning without
|
|
|
|
exhaustive search. This is on by default. See also the various
|
|
|
|
other GEQO_ settings.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>GEQO_EFFORT (<type>integer</type>)</term>
|
|
|
|
<term>GEQO_GENERATIONS (<type>integer</type>)</term>
|
|
|
|
<term>GEQO_POOL_SIZE (<type>integer</type>)</term>
|
|
|
|
<term>GEQO_RANDOM_SEED (<type>integer</type>)</term>
|
|
|
|
<term>GEQO_SELECTION_BIAS (<type>floating point</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Various tuning parameters for the genetic query optimization
|
|
|
|
algorithm: The pool size is the number of individuals in one
|
|
|
|
population. Valid values are between 128 and 1024. If it is
|
|
|
|
set to 0 (the default) a pool size of 2^(QS+1), where QS
|
2001-02-15 05:28:50 +01:00
|
|
|
is the number of FROM items in the query, is taken. The effort
|
2000-06-18 23:24:54 +02:00
|
|
|
is used to calculate a default for generations. Valid values
|
|
|
|
are between 1 and 80, 40 being the default. Generations
|
|
|
|
specifies the number of iterations in the algorithm. The
|
|
|
|
number must be a positive integer. If 0 is specified then
|
|
|
|
Effort * Log2(PoolSize) is used. The run time of the algorithm
|
|
|
|
is roughly proportional to the sum of pool size and
|
|
|
|
generations. The selection bias is the selective pressure
|
|
|
|
within the population. Values can be from 1.50 to 2.00; the
|
|
|
|
latter is the default. The random seed can be set to get
|
|
|
|
reproduceable results from the algorithm. If it is set to -1
|
|
|
|
then the algorithm behaves non-deterministically.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-12-03 15:36:47 +01:00
|
|
|
<term>GEQO_THRESHOLD (<type>integer</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2001-02-15 05:28:50 +01:00
|
|
|
Use genetic query optimization to plan queries with at least
|
|
|
|
this many FROM items involved. (Note that a JOIN construct
|
|
|
|
counts as only one FROM item.) The default is 11. For simpler
|
|
|
|
queries it is usually best to use the
|
2000-06-18 23:24:54 +02:00
|
|
|
deterministic, exhaustive planner.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>KSQO (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
The <firstterm>Key Set Query Optimizer</firstterm>
|
|
|
|
(<abbrev>KSQO</abbrev>) causes the query planner to convert
|
|
|
|
queries whose WHERE clause contains many OR'ed AND clauses
|
|
|
|
(such as <literal>WHERE (a=1 AND b=2) OR (a=2 AND b=3)
|
|
|
|
...</literal>) into a UNION query. This method can be faster
|
|
|
|
than the default implementation, but it doesn't necessarily
|
|
|
|
give exactly the same results, since UNION implicitly adds a
|
|
|
|
SELECT DISTINCT clause to eliminate identical output rows.
|
|
|
|
KSQO is commonly used when working with products like
|
|
|
|
<productname>Microsoft Access</productname>, which tend to
|
|
|
|
generate queries of this form.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The KSQO algorithm used to be absolutely essential for queries
|
|
|
|
with many OR'ed AND clauses, but in
|
|
|
|
<productname>Postgres</productname> 7.0 and later the standard
|
|
|
|
planner handles these queries fairly successfully. Hence the
|
|
|
|
default is OFF.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>RANDOM_PAGE_COST (<type>floating point</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Sets the query optimizer's estimate of the cost of a
|
|
|
|
nonsequentially fetched disk page. This is measured as a
|
|
|
|
multiple of the cost of a sequential page fetch.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
</variablelist>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<note>
|
|
|
|
<para>
|
|
|
|
Unfortunately, there is no well-defined method of determining
|
|
|
|
ideal values for the family of <quote>COST</quote> variables that
|
|
|
|
were just described. You are encouraged to experiment and share
|
|
|
|
your findings.
|
|
|
|
</para>
|
|
|
|
</note>
|
|
|
|
|
|
|
|
</sect2>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<sect2 id="logging">
|
|
|
|
<title>Logging and Debugging</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
<variablelist>
|
2000-07-12 19:38:53 +02:00
|
|
|
<varlistentry>
|
|
|
|
<term>DEBUG_ASSERTIONS (<type>boolean</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Turns on various assertion checks. This is a debugging aid. If
|
|
|
|
you are experiencing strange problems or crashes you might
|
|
|
|
want to turn this on, as it might expose programming mistakes.
|
2000-08-11 20:31:10 +02:00
|
|
|
To use this option, the macro <literal>USE_ASSERT_CHECKING</literal>
|
|
|
|
must be defined when Postgres is built (see the configure option
|
|
|
|
<literal>--enable-cassert</literal>). Note that
|
|
|
|
<literal>DEBUG_ASSERTIONS</literal> defaults to ON if Postgres
|
|
|
|
has been built this way.
|
2000-07-12 19:38:53 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
1999-05-20 07:39:29 +02:00
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>DEBUG_LEVEL (<type>integer</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
The higher this value is set, the more
|
|
|
|
<quote>debugging</quote> output of various sorts is generated
|
|
|
|
in the server log during operation. This option is 0 by
|
|
|
|
default, which means no debugging output. Values up to about 4
|
|
|
|
currently make sense.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
|
1999-05-20 07:39:29 +02:00
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>DEBUG_PRINT_PARSE (<type>boolean</type>)</term>
|
|
|
|
<term>DEBUG_PRINT_PLAN (<type>boolean</type>)</term>
|
|
|
|
<term>DEBUG_PRINT_REWRITTEN (<type>boolean</type>)</term>
|
|
|
|
<term>DEBUG_PRINT_QUERY (<type>boolean</type>)</term>
|
|
|
|
<term>DEBUG_PRETTY_PRINT (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
For any executed query, prints either the query, the parse
|
|
|
|
tree, the execution plan, or the query rewriter output to the
|
|
|
|
server log. <option>DEBUG_PRETTY_PRINT</option> selects are
|
|
|
|
nicer but longer output format.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-12-03 15:36:47 +01:00
|
|
|
<term>HOSTNAME_LOOKUP (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
By default, connection logs only show the IP address of the
|
|
|
|
connecting host. If you want it to show the host name you can
|
|
|
|
turn this on, but depending on your host name resolution setup
|
|
|
|
it might impose a non-negligible performance penalty. This
|
|
|
|
option can only be set at server start.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>LOG_CONNECTIONS (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Prints a line informing about each successful connection to
|
|
|
|
the server log. This is off by default, although it is
|
|
|
|
probably very useful. This option can only be set at server
|
|
|
|
start.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>LOG_PID (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Prefixes each server log message with the process id of the
|
|
|
|
backend process. This is useful to sort out which messages
|
|
|
|
pertain to which connection. The default is off.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>LOG_TIMESTAMP (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Prefixes each server log message with a timestamp. The default
|
|
|
|
is off.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>SHOW_QUERY_STATS (<type>boolean</type>)</term>
|
|
|
|
<term>SHOW_PARSER_STATS (<type>boolean</type>)</term>
|
|
|
|
<term>SHOW_PLANNER_STATS (<type>boolean</type>)</term>
|
|
|
|
<term>SHOW_EXECUTOR_STATS (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
For each query, write performance statistics of the respective
|
|
|
|
module to the server log. This is a crude profiling
|
|
|
|
instrument.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-12-03 15:36:47 +01:00
|
|
|
<term>SHOW_SOURCE_PORT (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-12-03 15:36:47 +01:00
|
|
|
Shows the outgoing port number of the connecting host in the
|
|
|
|
connection log messages. You could trace back the port number
|
|
|
|
to find out what user initiated the connection. Other than
|
|
|
|
that it's pretty useless and therefore off by default. This
|
|
|
|
option can only be set at server start.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>SYSLOG (<type>integer</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
<productname>Postgres</productname> allows the use of
|
|
|
|
<application>syslog</application> for logging. If this option
|
|
|
|
is set to 1, messages go both to syslog and the standard
|
|
|
|
output. A setting of 2 sends output only to syslog. (Some
|
|
|
|
messages will still go to the standard output/error.) The
|
|
|
|
default is 0, which means syslog is off. This option must be
|
|
|
|
set at server start.
|
|
|
|
</para>
|
|
|
|
<para>
|
|
|
|
To use syslog, the build of
|
|
|
|
<productname>Postgres</productname> must be configured with
|
|
|
|
the <option>--enable-syslog</option> option.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2000-11-13 22:35:03 +01:00
|
|
|
<varlistentry>
|
|
|
|
<term>SYSLOG_FACILITY (<type>string</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-11-14 20:13:27 +01:00
|
|
|
This option determines the <application>syslog</application>
|
|
|
|
<quote>facility</quote> to be used when syslog is enabled.
|
|
|
|
You may choose from LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4,
|
|
|
|
LOCAL5, LOCAL6, LOCAL7; the default is LOCAL0. See also the
|
|
|
|
documentation of your system's
|
|
|
|
<application>syslog</application>.
|
2000-11-13 22:35:03 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-11-14 20:13:27 +01:00
|
|
|
<term>SYSLOG_IDENT (<type>string</type>)</term>
|
2000-11-13 22:35:03 +01:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-11-14 20:13:27 +01:00
|
|
|
If logging to syslog is enabled, this option determines the
|
|
|
|
program name used to identify
|
|
|
|
<productname>PostgreSQL</productname> messages in
|
|
|
|
<application>syslog</application> log messages. The default
|
|
|
|
is <quote>postgres</quote>.
|
2000-11-13 22:35:03 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
1999-05-20 07:39:29 +02:00
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>TRACE_NOTIFY (<type>boolean</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Generates a great amount of debugging output for the
|
|
|
|
<command>LISTEN</command> and <command>NOTIFY</command>
|
|
|
|
commands.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
2000-06-18 23:24:54 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
</variablelist>
|
|
|
|
</para>
|
|
|
|
</sect2>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<sect2 id="runtime-config-general">
|
|
|
|
<title>General operation</title>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<para>
|
|
|
|
<variablelist>
|
|
|
|
<varlistentry>
|
|
|
|
<term>DEADLOCK_TIMEOUT (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-07-18 00:32:44 +02:00
|
|
|
This is the amount of time, in milliseconds, to wait on a lock
|
|
|
|
before checking to see if there is a deadlock condition or not.
|
|
|
|
The check for deadlock is relatively slow, so we don't want to
|
|
|
|
run it every time we wait for a lock. We (optimistically?)
|
|
|
|
assume that deadlocks are not common in production applications,
|
|
|
|
and just wait on the lock for awhile before starting to ask
|
|
|
|
questions about whether it can ever get unlocked.
|
|
|
|
Increasing this value reduces the amount of time wasted in
|
|
|
|
needless deadlock checks, but slows down reporting of real deadlock
|
|
|
|
errors. The default is 1000 (i.e., one second), which is probably
|
|
|
|
about the smallest value you would want in practice. On a heavily
|
|
|
|
loaded server you might want to raise it. Ideally the setting
|
|
|
|
should exceed your typical transaction time, so as to improve the
|
|
|
|
odds that the lock will be released before the waiter decides to
|
|
|
|
check for deadlock.
|
|
|
|
This option can only be set at server start.
|
2000-06-18 23:24:54 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>FSYNC (<type>boolean</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2001-02-18 06:30:12 +01:00
|
|
|
If this option is on, the <productname>Postgres</> backend
|
2000-07-16 16:47:57 +02:00
|
|
|
will use the <function>fsync()</> system call in several
|
|
|
|
places to make sure that updates are physically written to
|
2001-02-18 06:30:12 +01:00
|
|
|
disk and do not hang around in the kernel buffer cache. This
|
2000-07-16 16:47:57 +02:00
|
|
|
increases the chance that a database installation will still
|
2001-02-18 06:30:12 +01:00
|
|
|
be usable after an operating system or hardware crash by a
|
2000-07-16 16:47:57 +02:00
|
|
|
large amount. (Crashes of the database server itself do
|
|
|
|
<emphasis>not</> affect this consideration.)
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2001-02-18 06:30:12 +01:00
|
|
|
However, this operation slows down <productname>Postgres</>,
|
|
|
|
because at all those points it has
|
2000-07-16 16:47:57 +02:00
|
|
|
to block and wait for the operating system to flush the
|
|
|
|
buffers. Without <function>fsync</>, the operating system is
|
|
|
|
allowed to do its best in buffering, sorting, and delaying
|
2001-02-18 06:30:12 +01:00
|
|
|
writes, which can make for a considerable perfomance
|
|
|
|
increase. However, if the system crashes, the results of the
|
|
|
|
last few committed transactions may be lost in part or whole;
|
|
|
|
in the worst case, unrecoverable data corruption may occur.
|
2000-07-16 16:47:57 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
This option is the subject of an eternal debate in the
|
|
|
|
<productname>Postgres</> user and developer communities. Some
|
|
|
|
always leave it off, some turn it off only for bulk loads,
|
|
|
|
where there is a clear restart point if something goes wrong,
|
|
|
|
some leave it on just to be on the safe side. Because it is
|
|
|
|
the safe side, on is also the default. If you trust your
|
2001-02-18 06:30:12 +01:00
|
|
|
operating system, your hardware, and your utility company (or
|
|
|
|
better your UPS), you might want to disable fsync.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
It should be noted that the performance penalty from doing
|
|
|
|
fsyncs is considerably less in <productname>Postgres</> version
|
|
|
|
7.1 than it was in prior releases. If you previously suppressed
|
|
|
|
fsyncs because of performance problems, you may wish to reconsider
|
|
|
|
your choice.
|
2000-06-18 23:24:54 +02:00
|
|
|
</para>
|
XLOG (and related) changes:
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
|
|
|
|
|
|
|
<para>
|
|
|
|
This option can only be set at server start or in the
|
|
|
|
<filename>postgresql.conf</filename> file.
|
|
|
|
</para>
|
2000-06-18 23:24:54 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-11-14 19:11:32 +01:00
|
|
|
<varlistentry>
|
|
|
|
<term>KRB_SERVER_KEYFILE (<type>string</type>)</term>
|
2000-08-25 12:00:35 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the location of the Kerberos server key file. See
|
|
|
|
<xref linkend="kerberos-auth"> for details.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<varlistentry>
|
2000-07-12 19:38:53 +02:00
|
|
|
<term>MAX_CONNECTIONS (<type>integer</type>)</term>
|
2000-06-18 23:24:54 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Determines how many concurrent connections the database server
|
2000-07-12 19:38:53 +02:00
|
|
|
will allow. The default is 32. There is also a compiled-in
|
2000-07-18 00:32:44 +02:00
|
|
|
hard upper limit on this value, which is typically 1024
|
|
|
|
(both numbers can be altered when compiling the server). This
|
2000-07-12 19:38:53 +02:00
|
|
|
parameter can only be set at server start.
|
2000-06-18 23:24:54 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<varlistentry>
|
|
|
|
<term>MAX_EXPR_DEPTH (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the maximum expression nesting depth that the parser will
|
|
|
|
accept. The default value is high enough for any normal query,
|
|
|
|
but you can raise it if you need to. (But if you raise it too
|
|
|
|
high, you run the risk of backend crashes due to stack
|
|
|
|
overflow.)
|
|
|
|
</para>
|
1999-05-20 07:39:29 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<term>PORT (<type>integer</type>)</term>
|
1999-05-20 07:39:29 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
The TCP port the server listens on; 5432 by default. This
|
|
|
|
option can only be set at server start.
|
1999-05-20 07:39:29 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-08-28 13:57:41 +02:00
|
|
|
<term>SHARED_BUFFERS (<type>integer</type>)</term>
|
2000-04-09 01:12:01 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-06-18 23:24:54 +02:00
|
|
|
Sets the number of shared memory buffers the database server
|
|
|
|
will use. The default is 64. Each buffer is typically 8192
|
|
|
|
bytes. This option can only be set at server start.
|
2000-04-09 01:12:01 +02:00
|
|
|
</para>
|
2000-10-08 11:25:38 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>SILENT_MODE (<type>bool</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-12-03 15:36:47 +01:00
|
|
|
Runs postmaster silently. If this option is set, postmaster
|
2000-10-08 11:25:38 +02:00
|
|
|
will automatically run in background and any controlling ttys
|
2000-12-03 15:36:47 +01:00
|
|
|
are disassociated, thus no messages are written to stdout or
|
|
|
|
stderr (same effect as postmaster's -S option). Unless some
|
|
|
|
logging system such as syslog is enabled, using this option is
|
|
|
|
discouraged since it makes it impossible to see error
|
2000-10-08 11:25:38 +02:00
|
|
|
messages.
|
|
|
|
</para>
|
2000-04-09 01:12:01 +02:00
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<varlistentry>
|
|
|
|
<term>SORT_MEM (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Specifies the amount of memory to be used by internal sorts
|
|
|
|
and hashes before resorting to temporary disk files. The value
|
|
|
|
is specified in kilobytes, and defaults to 512 kilobytes. Note
|
|
|
|
that for a complex query, several sorts and/or hashes might be
|
|
|
|
running in parallel, and each one will be allowed to use as
|
|
|
|
much memory as this value specifies before it starts to put
|
|
|
|
data into temporary files.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2000-06-23 00:31:24 +02:00
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>SQL_INHERITANCE (<type>bool</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
This controls the inheritance semantics, in particular whether
|
|
|
|
subtables are included into the consideration of various
|
|
|
|
commands by default. This was not the case in versions prior
|
2000-07-12 19:38:53 +02:00
|
|
|
to 7.1. If you need the old behaviour you can set this
|
|
|
|
variable to off, but in the long run you are encouraged to
|
|
|
|
change your applications to use the <literal>ONLY</literal>
|
|
|
|
keyword to exclude subtables. See the SQL language reference
|
|
|
|
and the <citetitle>User's Guide</citetitle> for more
|
|
|
|
information about inheritance.
|
2000-06-23 00:31:24 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2000-09-06 21:54:52 +02:00
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>SSL (<type>boolean</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Enables <acronym>SSL</> connections. Please read
|
2000-10-20 16:00:49 +02:00
|
|
|
<xref linkend="ssl-tcp"> before using this. The default
|
2000-09-06 21:54:52 +02:00
|
|
|
is off.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>TCPIP_SOCKET (<type>boolean</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
If this is true, then the server will accept TCP/IP
|
|
|
|
connections. Otherwise only local Unix domain socket
|
|
|
|
connections are accepted. It is off by default. This option
|
|
|
|
can only be set at server start.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2000-11-01 22:14:03 +01:00
|
|
|
|
2000-11-14 19:11:32 +01:00
|
|
|
<varlistentry>
|
2000-12-01 00:20:51 +01:00
|
|
|
<term>UNIX_SOCKET_DIRECTORY (<type>string</type>)</term>
|
2000-11-14 19:11:32 +01:00
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-12-01 00:20:51 +01:00
|
|
|
Specifies the directory of the Unix-domain socket on which the
|
2000-11-14 19:11:32 +01:00
|
|
|
<application>postmaster</application> is to listen for
|
2000-12-01 00:20:51 +01:00
|
|
|
connections from client applications. The default is normally
|
|
|
|
<filename>/tmp</filename>, but can be changed at build time.
|
2000-11-14 19:11:32 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2000-11-01 22:14:03 +01:00
|
|
|
<varlistentry>
|
|
|
|
<term>UNIX_SOCKET_GROUP (<type>string</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the group owner of the Unix domain socket. (The owning
|
|
|
|
user of the socket is always the user that starts the
|
|
|
|
postmaster.) In combination with the option
|
|
|
|
<option>UNIX_SOCKET_PERMISSIONS</option> this can be used as
|
|
|
|
an additional access control mechanism for this socket type.
|
|
|
|
By default this is the empty string, which uses the default
|
|
|
|
group for the current user. This option can only be set at
|
|
|
|
server start.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>UNIX_SOCKET_PERMISSIONS (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Sets the access permissions of the Unix domain socket. Unix
|
|
|
|
domain sockets use the usual Unix file system permission set.
|
|
|
|
The option value is expected to be an numeric mode
|
|
|
|
specification in the form accepted by the
|
|
|
|
<function>chmod</function> and <function>umask</function>
|
|
|
|
system calls. (To use the customary octal format the number
|
|
|
|
must start with a <literal>0</literal> (zero).)
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The default permissions are <literal>0777</literal>, meaning
|
|
|
|
anyone can connect. Reasonable alternatives would be
|
|
|
|
<literal>0770</literal> (only user and group, see also under
|
|
|
|
<option>UNIX_SOCKET_GROUP</option>) and
|
|
|
|
<literal>0700</literal> (only user). (Note that actually for
|
|
|
|
a Unix socket, only write permission matters and there is no
|
|
|
|
point in setting or revoking read or execute permissions.)
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
This access control mechanism is independent from the one
|
|
|
|
described in <xref linkend="client-authentication">.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
This option can only be set at server start.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2000-11-15 19:36:06 +01:00
|
|
|
<varlistentry>
|
|
|
|
<term>VIRTUAL_HOST (<type>string</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Specifies the TCP/IP hostname or address on which the
|
|
|
|
<application>postmaster</application> is to listen for
|
2000-12-01 00:20:51 +01:00
|
|
|
connections from client applications. Defaults to
|
|
|
|
listening on all configured addresses (including localhost).
|
2000-11-15 19:36:06 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
1999-05-20 07:39:29 +02:00
|
|
|
</variablelist>
|
2000-06-18 23:24:54 +02:00
|
|
|
</para>
|
1999-05-20 07:39:29 +02:00
|
|
|
</sect2>
|
2000-06-18 23:24:54 +02:00
|
|
|
|
2001-01-25 00:15:19 +01:00
|
|
|
<sect2 id="runtime-config-wal">
|
|
|
|
<title>WAL</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
See also <xref linkend="wal-configuration"> for details on WAL
|
|
|
|
tuning.
|
|
|
|
|
|
|
|
<variablelist>
|
XLOG (and related) changes:
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
|
|
|
<varlistentry>
|
|
|
|
<term>CHECKPOINT_SEGMENTS (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Maximum distance between automatic WAL checkpoints, in logfile
|
|
|
|
segments (each segment is normally 16 megabytes).
|
|
|
|
This option can only be set at server start or in the
|
|
|
|
<filename>postgresql.conf</filename> file.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
2001-01-25 00:15:19 +01:00
|
|
|
<varlistentry>
|
|
|
|
<term>CHECKPOINT_TIMEOUT (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
XLOG (and related) changes:
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
|
|
|
Maximum time between automatic WAL checkpoints, in seconds.
|
|
|
|
This option can only be set at server start or in the
|
|
|
|
<filename>postgresql.conf</filename> file.
|
2001-01-25 00:15:19 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>WAL_BUFFERS (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2001-03-16 06:44:33 +01:00
|
|
|
Number of disk-page buffers in shared memory for WAL log.
|
|
|
|
This option can only be set at server start.
|
2001-01-25 00:15:19 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>WAL_DEBUG (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
If non-zero, turn on WAL-related debugging output on standard
|
|
|
|
error.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>WAL_FILES (<type>integer</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Number of log files that are created in advance at checkpoint
|
XLOG (and related) changes:
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
|
|
|
time. This option can only be set at server start or in the
|
|
|
|
<filename>postgresql.conf</filename> file.
|
2001-01-25 00:15:19 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2001-03-16 06:44:33 +01:00
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>WAL_SYNC_METHOD (<type>string</type>)</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
Method used for forcing WAL updates out to disk. Possible
|
|
|
|
values are
|
|
|
|
<literal>FSYNC</> (call fsync() at each commit),
|
|
|
|
<literal>FDATASYNC</> (call fdatasync() at each commit),
|
|
|
|
<literal>OPEN_SYNC</> (write WAL files with open() option O_SYNC), or
|
|
|
|
<literal>OPEN_DATASYNC</> (write WAL files with open() option O_DSYNC).
|
|
|
|
Not all of these choices are available on all platforms.
|
|
|
|
This option can only be set at server start or in the
|
|
|
|
<filename>postgresql.conf</filename> file.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
2001-01-25 00:15:19 +01:00
|
|
|
</variablelist>
|
|
|
|
</para>
|
|
|
|
</sect2>
|
|
|
|
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<sect2 id="runtime-config-short">
|
|
|
|
<title>Short options</title>
|
|
|
|
<para>
|
|
|
|
For convenience there are also single letter option switches
|
|
|
|
available for many parameters. They are described in the following
|
|
|
|
table.
|
|
|
|
|
|
|
|
<table>
|
|
|
|
<title>Short option key</title>
|
|
|
|
<tgroup cols="3">
|
|
|
|
<colspec colnum="3" align="center">
|
|
|
|
<thead>
|
|
|
|
<row>
|
|
|
|
<entry>Short option</entry>
|
|
|
|
<entry>Equivalent</entry>
|
|
|
|
<entry>Remark</entry>
|
|
|
|
</row>
|
|
|
|
</thead>
|
|
|
|
<tbody>
|
|
|
|
<row>
|
|
|
|
<entry>-B <replaceable>x</replaceable></entry>
|
2000-08-28 13:57:41 +02:00
|
|
|
<entry>shared_buffers = <replaceable>x</replaceable></entry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<entry></entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-d <replaceable>x</replaceable></entry>
|
|
|
|
<entry>debug_level = <replaceable>x</replaceable></entry>
|
|
|
|
<entry></entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-F</entry>
|
|
|
|
<entry>fsync = off</entry>
|
|
|
|
<entry></entry>
|
|
|
|
</row>
|
2000-11-15 19:36:06 +01:00
|
|
|
<row>
|
|
|
|
<entry>-h <replaceable>x</replaceable></entry>
|
|
|
|
<entry>virtual_host = <replaceable>x</replaceable></entry>
|
|
|
|
<entry></entry>
|
|
|
|
</row>
|
2000-06-18 23:24:54 +02:00
|
|
|
<row>
|
|
|
|
<entry>-i</entry>
|
2000-07-12 19:38:53 +02:00
|
|
|
<entry>tcpip_socket = on</entry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<entry></entry>
|
2000-12-01 00:20:51 +01:00
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-k <replaceable>x</replaceable></entry>
|
|
|
|
<entry>unix_socket_directory = <replaceable>x</replaceable></entry>
|
|
|
|
<entry></entry>
|
2000-06-18 23:24:54 +02:00
|
|
|
</row>
|
2000-09-06 21:54:52 +02:00
|
|
|
<row>
|
|
|
|
<entry>-l</entry>
|
|
|
|
<entry>ssl = on</entry>
|
|
|
|
<entry></entry>
|
|
|
|
</row>
|
2000-06-18 23:24:54 +02:00
|
|
|
<row>
|
|
|
|
<entry>-N <replaceable>x</replaceable></entry>
|
2000-07-12 19:38:53 +02:00
|
|
|
<entry>max_connections = <replaceable>x</replaceable></entry>
|
2000-06-18 23:24:54 +02:00
|
|
|
<entry></entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-p <replaceable>x</replaceable></entry>
|
|
|
|
<entry>port = <replaceable>x</replaceable></entry>
|
|
|
|
<entry></entry>
|
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry>-fi, -fh, -fm, -fn, -fs, -ft</entry>
|
|
|
|
<entry>enable_indexscan=off, enable_hashjoin=off,
|
|
|
|
enable_mergejoin=off, enable_nestloop=off, enable_seqscan=off,
|
|
|
|
enable_tidscan=off</entry>
|
|
|
|
<entry>*</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-S <replaceable>x</replaceable></entry>
|
|
|
|
<entry>sort_mem = <replaceable>x</replaceable></entry>
|
|
|
|
<entry>*</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-s</entry>
|
|
|
|
<entry>show_query_stats = on</entry>
|
|
|
|
<entry>*</entry>
|
|
|
|
</row>
|
|
|
|
<row>
|
|
|
|
<entry>-tpa, -tpl, -te</entry>
|
|
|
|
<entry>show_parser_stats=on, show_planner_stats=on, show_executor_stats=on</entry>
|
|
|
|
<entry>*</entry>
|
|
|
|
</row>
|
|
|
|
</tbody>
|
|
|
|
</tgroup>
|
|
|
|
</table>
|
|
|
|
For historical reasons, options marked <quote>*</quote> must be
|
|
|
|
passed to the individual backend process via the
|
|
|
|
<option>-o</option> postmaster option, for example,
|
|
|
|
<screen>
|
|
|
|
> <userinput>postmaster -o '-S 1024 -s'</userinput>
|
|
|
|
</screen>
|
|
|
|
or via <envar>PGOPTIONS</envar> from the client side, as explained
|
|
|
|
above.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
</sect2>
|
|
|
|
</sect1>
|
|
|
|
|
2000-07-15 23:35:47 +02:00
|
|
|
|
2000-07-22 16:49:01 +02:00
|
|
|
<sect1 id="kernel-resources">
|
|
|
|
<title>Managing Kernel Resources</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
A large <productname>Postgres</> installation can quickly hit
|
|
|
|
various operating system resource limits. (On some systems, the
|
|
|
|
factory defaults are so low that you don't even need a really
|
|
|
|
<quote>large</> installation.) If you have encountered this kind of
|
|
|
|
problem then keep reading.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<sect2 id="sysvipc">
|
|
|
|
<title>Shared Memory and Semaphores</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Shared memory and semaphores are collectively referred to as
|
|
|
|
<quote>System V IPC</> (together with message queues, which are
|
|
|
|
not relevant for <productname>Postgres</>). Almost all modern
|
|
|
|
operating systems provide these features, but not all of them have
|
|
|
|
them turned on or sufficiently sized by default, especially
|
|
|
|
systems with BSD heritage. (For the QNX port,
|
|
|
|
<productname>Postgres</> provides its own replacement
|
|
|
|
implementation of these facilities.)
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The complete lack of these facilities is usually manifested by an
|
|
|
|
<errorname>Illegal system call</> error upon postmaster start. In
|
|
|
|
that case there's nothing left to do but to reconfigure your
|
|
|
|
kernel -- <productname>Postgres</> won't work without them.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
When <productname>Postgres</> exceeds one of the various hard
|
|
|
|
limits of the IPC resources then the postmaster will refuse to
|
|
|
|
start up and should leave a marginally instructive error message
|
|
|
|
about which problem was encountered and what needs to be done
|
2000-12-17 12:22:00 +01:00
|
|
|
about it. (See also <xref linkend="postmaster-start-failures">.)
|
|
|
|
The relevant kernel parameters are named
|
2000-11-10 17:32:09 +01:00
|
|
|
consistently across different systems; <xref
|
2000-07-22 16:49:01 +02:00
|
|
|
linkend="sysvipc-parameters"> gives an overview. The methods to
|
|
|
|
set them, however, vary; suggestions for some platforms are given
|
2000-12-30 16:03:09 +01:00
|
|
|
below. Be warned that it is often necessary to reboot your
|
2000-11-10 17:32:09 +01:00
|
|
|
machine at least, possibly even recompile the kernel, to change these
|
2000-07-22 16:49:01 +02:00
|
|
|
settings.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
|
|
<table id="sysvipc-parameters">
|
|
|
|
<title>System V IPC parameters</>
|
|
|
|
|
|
|
|
<tgroup cols="3">
|
|
|
|
<thead>
|
|
|
|
<row>
|
|
|
|
<entry>Name</>
|
|
|
|
<entry>Description</>
|
|
|
|
<entry>Reasonable values</>
|
|
|
|
</row>
|
|
|
|
</thead>
|
|
|
|
|
|
|
|
<tbody>
|
|
|
|
<row>
|
|
|
|
<entry><varname>SHMMAX</></>
|
|
|
|
<entry>Maximum size of shared memory segment (bytes)</>
|
|
|
|
<entry>512 kB + 8192 * buffers + extra ... infinity</entry>
|
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SHMMIN</></>
|
|
|
|
<entry>Minimum size of shared memory segment (bytes)</>
|
2000-12-17 12:22:00 +01:00
|
|
|
<entry>1 (at most about 256 kB)</>
|
2000-07-22 16:49:01 +02:00
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SHMSEG</></>
|
|
|
|
<entry>Maximum number of shared memory segments per process</>
|
2000-12-17 12:22:00 +01:00
|
|
|
<entry>only 1 segment is needed, but the default is much higher</>
|
2000-07-22 16:49:01 +02:00
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SHMMNI</></>
|
|
|
|
<entry>Maximum number of shared memory segments system-wide</>
|
|
|
|
<entry>like <varname>SHMSEG</> + room for other applications</>
|
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SEMMNI</></>
|
|
|
|
<entry>Maximum number of semaphore identifiers (i.e., sets)</>
|
2000-11-10 17:32:09 +01:00
|
|
|
<entry>>= ceil(max_connections / 16)</>
|
2000-07-22 16:49:01 +02:00
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SEMMNS</></>
|
|
|
|
<entry>Maximum number of semaphores system-wide</>
|
2000-12-17 12:22:00 +01:00
|
|
|
<entry>ceil(max_connections / 16) * 17 + room for other applications</>
|
2000-07-22 16:49:01 +02:00
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SEMMSL</></>
|
|
|
|
<entry>Maximum number of semaphores per set</>
|
2000-12-17 12:22:00 +01:00
|
|
|
<entry>>= 17</>
|
2000-07-22 16:49:01 +02:00
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SEMMAP</></>
|
|
|
|
<entry>Number of entries in semaphore map</>
|
|
|
|
<entry>see text</>
|
|
|
|
</row>
|
|
|
|
|
|
|
|
<row>
|
|
|
|
<entry><varname>SEMVMX</></>
|
|
|
|
<entry>Maximum value of semaphore</>
|
|
|
|
<entry>>= 255 (The default is often 32767, don't change unless asked to.)</>
|
|
|
|
</row>
|
|
|
|
|
|
|
|
</tbody>
|
|
|
|
</tgroup>
|
|
|
|
</table>
|
|
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The most important shared memory parameter is <varname>SHMMAX</>,
|
|
|
|
the maximum size, in bytes, that a shared memory segment can have.
|
|
|
|
If you get an error message from <function>shmget</> along the
|
|
|
|
lines of <errorname>Invalid argument</> then it is possible that
|
|
|
|
this limit has been exceeded. The size of the required shared
|
|
|
|
memory segments varies both with the number of requested buffers
|
|
|
|
(<option>-B</> option) and the number of allowed connections
|
|
|
|
(<option>-N</> option), although the former is the dominant item.
|
|
|
|
(You can therefore, as a temporary solution, lower these settings
|
|
|
|
to get rid of the failures.) As a rough approximation you can
|
|
|
|
estimate the required segment size as the number of buffers times
|
|
|
|
the block size (8192 kB by default) plus ample overhead (at least
|
|
|
|
half a megabyte). Any error message you might get will contain the
|
2000-12-17 12:22:00 +01:00
|
|
|
size of the failed allocation.
|
2000-07-22 16:49:01 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Less likely to cause problems is the minimum size for shared
|
2000-12-17 12:22:00 +01:00
|
|
|
memory segments (<varname>SHMMIN</>), which should be at most
|
|
|
|
somewhere around 256 kB for <productname>Postgres</> (it is
|
|
|
|
usually just 1). The maximum number of segments system-wide
|
|
|
|
(<varname>SHMMNI</>) or per-process (<varname>SHMSEG</>) should
|
|
|
|
not cause a problem unless your system has them set to zero. Some
|
|
|
|
systems also have a limit on the total amount of shared memory in
|
|
|
|
the system; see the platform-specific instructions below.
|
2000-07-22 16:49:01 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
<productname>Postgres</> uses one semaphore per allowed connection
|
2000-12-17 12:22:00 +01:00
|
|
|
(<option>-N</> option), in sets of 16. Each such set will also
|
|
|
|
contain a 17th semaphore which contains a <quote>magic
|
|
|
|
number</quote>, to avoid collision with semaphore sets used by
|
|
|
|
other applications. The maximum number of semaphores in the system
|
|
|
|
is set by <varname>SEMMNS</>, which consequently must be at least
|
|
|
|
as high as the connection setting plus one extra for each 16
|
|
|
|
allowed connections (see the formula in <xref
|
|
|
|
linkend="sysvipc-parameters">. The parameter <varname>SEMMNI</>
|
|
|
|
determines the limit on the number of semaphore sets that can
|
|
|
|
exist on the system at one time. Hence this parameter must be at
|
|
|
|
least <literal>ceil(max_connections / 16)</>. Lowering the number
|
|
|
|
of allowed connections is a temporary workaround for failures,
|
|
|
|
which are usually confusingly worded <quote><errorname>No space
|
|
|
|
left on device</></>, from the function <function>semget()</>.
|
2000-07-22 16:49:01 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
In some cases it might also turn out to be necessary to increase
|
|
|
|
<varname>SEMMAP</> to be at least on the order of
|
|
|
|
<varname>SEMMNS</>. This parameter defines the size of the
|
|
|
|
semaphore resource map, in which each contiguous block of available
|
|
|
|
semaphores needs an entry. When a semaphore set is freed it is
|
|
|
|
either added to an existing entry that is adjacent to the freed
|
|
|
|
block or it is registered under a new map entry. If the map is
|
2000-11-10 17:32:09 +01:00
|
|
|
full, the freed semaphores get lost (until reboot). Fragmentation
|
2000-07-22 16:49:01 +02:00
|
|
|
of the semaphore space could therefore over time lead to less
|
|
|
|
available semaphores than there should be.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The <varname>SEMMSL</> parameter, which determines how many
|
2000-12-17 12:22:00 +01:00
|
|
|
semaphores can be in a set, must be at least 17 for
|
2000-07-22 16:49:01 +02:00
|
|
|
<productname>Postgres</>.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2000-11-10 17:32:09 +01:00
|
|
|
Various other settings related to <quote>semaphore undo</>, such as
|
|
|
|
<varname>SEMMNU</> and <varname>SEMUME</>, are not of concern
|
|
|
|
for <productname>Postgres</>.
|
2000-07-22 16:49:01 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
<variablelist>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>BSD/OS</>
|
|
|
|
<listitem>
|
|
|
|
<formalpara>
|
|
|
|
<title>Shared Memory</>
|
|
|
|
<para>
|
|
|
|
By default, only 4 MB of shared memory is supported. Keep in
|
|
|
|
mind that shared memory is not pageable; it is locked in RAM.
|
2001-02-16 20:43:52 +01:00
|
|
|
The shared memory parameters are:
|
|
|
|
<programlisting>
|
|
|
|
#define SHMMAX /* max shared memory segment size (bytes) */
|
|
|
|
#define SHMMIN /* min shared memory segment size (bytes) */
|
|
|
|
#define SHMMNI /* max number of shared memory identifiers */
|
|
|
|
#define SHMSEG /* max shared memory segments per process */
|
|
|
|
#define SHMALL /* max amount of shared memory (pages) */
|
|
|
|
</programlisting>
|
|
|
|
|
2001-02-16 17:10:06 +01:00
|
|
|
To increase the number of buffers supported by the postmaseter, add the
|
|
|
|
following to your kernel config file. A <varname>SHMALL</> value of 1024
|
|
|
|
represents 4MB of shared memory. Increase it accordingly:
|
2000-07-22 16:49:01 +02:00
|
|
|
<programlisting>
|
2001-02-16 17:10:06 +01:00
|
|
|
options "SHMALL=4096"
|
|
|
|
options "SHMMAX=\(SHMALL*PAGE_SIZE\)"
|
2000-07-22 16:49:01 +02:00
|
|
|
</programlisting>
|
|
|
|
</para>
|
|
|
|
</formalpara>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
For those running 4.1 or later, just recompile the kernel and
|
|
|
|
reboot. For those running earlier releases, use
|
|
|
|
<application>bpatch</> to find the <varname>sysptsize</> value
|
|
|
|
for the current kernel. This is computed dynamically at
|
|
|
|
bootup.
|
|
|
|
<screen>
|
|
|
|
$ <userinput>bpatch -r sysptsize</>
|
|
|
|
<computeroutput>0x9 = 9</>
|
|
|
|
</screen>
|
|
|
|
Next, change <varname>SYSPTSIZE</> to a hard-coded value. Use
|
|
|
|
the bpatch value, plus add 1 for every additional 4 MB of
|
|
|
|
shared memory you desire.
|
|
|
|
<programlisting>
|
2001-02-16 17:10:06 +01:00
|
|
|
options "SYSPTSIZE=13"
|
2000-07-22 16:49:01 +02:00
|
|
|
</programlisting>
|
|
|
|
<varname>sysptsize</> can not be changed by sysctl on the fly.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<formalpara>
|
|
|
|
<title>Semaphores</>
|
|
|
|
<para>
|
|
|
|
You may need to increase the number of semaphores. By
|
|
|
|
default, <productname>Postgres</> allocates 32 semaphores,
|
|
|
|
one for each backend connection. This is just over half the
|
|
|
|
default system total of 60.
|
|
|
|
</para>
|
|
|
|
</formalpara>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The defaults are in <filename>/sys/sys/sem.h</>:
|
|
|
|
<programlisting>
|
|
|
|
#define SEMMNI 10 /* # of semaphore identifiers */
|
2001-02-16 20:27:19 +01:00
|
|
|
|
2000-07-22 16:49:01 +02:00
|
|
|
#define SEMMNS 60 /* # of semaphores in system */
|
2001-02-16 20:27:19 +01:00
|
|
|
|
2000-07-22 16:49:01 +02:00
|
|
|
#define SEMUME 10 /* max # of undo entries per process */
|
2001-02-16 20:27:19 +01:00
|
|
|
|
2000-07-22 16:49:01 +02:00
|
|
|
#define SEMMNU 30 /* # of undo structures in system */
|
|
|
|
</programlisting>
|
|
|
|
Set the values you want in your kernel config file, e.g.:
|
|
|
|
<programlisting>
|
|
|
|
options "SEMMNI=40"
|
|
|
|
options "SEMMNS=240"
|
|
|
|
options "SEMUME=40"
|
|
|
|
options "SEMMNU=120"
|
|
|
|
</programlisting>
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2001-01-08 22:01:54 +01:00
|
|
|
<term>FreeBSD</term>
|
|
|
|
<term>OpenBSD</term>
|
2000-07-22 16:49:01 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
The options <varname>SYSVSHM</> and <varname>SYSVSEM</> need
|
|
|
|
to be enabled when the kernel is compiled. (They are by
|
|
|
|
default.) The maximum size of shared memory is determined by
|
|
|
|
the option <varname>SHMMAXPGS</> (in pages). The following
|
2000-11-10 17:32:09 +01:00
|
|
|
shows an example of how to set the various parameters:
|
2000-07-22 16:49:01 +02:00
|
|
|
<programlisting>
|
2001-01-08 22:01:54 +01:00
|
|
|
options SYSVSHM
|
|
|
|
options SHMMAXPGS=4096
|
|
|
|
options SHMSEG=256
|
|
|
|
|
|
|
|
options SYSVSEM
|
|
|
|
options SEMMNI=256
|
|
|
|
options SEMMNS=512
|
|
|
|
options SEMMNU=256
|
2000-07-22 16:49:01 +02:00
|
|
|
options SEMMAP=256
|
|
|
|
</programlisting>
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
2000-12-17 12:22:00 +01:00
|
|
|
<term>HP-UX</>
|
2000-07-22 16:49:01 +02:00
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
The default settings tend to suffice for normal installations.
|
2000-12-17 12:22:00 +01:00
|
|
|
On <productname>HP-UX</> 10, the factory default for
|
2000-07-22 16:49:01 +02:00
|
|
|
<varname>SEMMNS</> is 128, which might be too low for larger
|
|
|
|
database sites.
|
|
|
|
</para>
|
|
|
|
<para>
|
|
|
|
IPC parameters can be set in the <application>System
|
|
|
|
Administration Manager</> (<acronym>SAM</>) under
|
|
|
|
<menuchoice><guimenu>Kernel
|
|
|
|
Configuration</><guimenuitem>Configurable Parameters</></>.
|
|
|
|
Hit <guibutton>Create A New Kernel</> when you're done.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>Linux</>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2000-12-17 12:22:00 +01:00
|
|
|
The default shared memory limit (both
|
|
|
|
<varname>SHMMAX</varname> and <varname>SHMALL</varname>) is 32
|
|
|
|
MB in 2.2 kernels, but it can be changed in the
|
|
|
|
<filename>proc</filename> file system (without reboot). For
|
|
|
|
example, to allow 128 MB:
|
|
|
|
<screen>
|
|
|
|
<prompt>$</prompt> <userinput>echo 134217728 >/proc/sys/kernel/shmall</userinput>
|
|
|
|
<prompt>$</prompt> <userinput>echo 134217728 >/proc/sys/kernel/shmmax</userinput>
|
|
|
|
</screen>
|
|
|
|
You could put these commands into a script run at boot-time.
|
|
|
|
</para>
|
|
|
|
|
2000-12-30 16:03:09 +01:00
|
|
|
<para>
|
|
|
|
Alternatively, you can use
|
|
|
|
<citerefentry><refentrytitle>sysctl</refentrytitle>
|
|
|
|
<manvolnum>8</manvolnum></citerefentry>, if available, to
|
|
|
|
control these parameters. Look for a file called
|
|
|
|
<filename>/etc/sysctl.conf</filename> and add lines like the
|
|
|
|
following to it:
|
|
|
|
<programlisting>
|
|
|
|
kernel.shmall = 134217728
|
|
|
|
kernel.shmmax = 134217728
|
|
|
|
</programlisting>
|
|
|
|
This file is usually processed at boot time, but
|
|
|
|
<application>sysctl</application> can also be called
|
|
|
|
explicitly later.
|
|
|
|
</para>
|
|
|
|
|
2000-12-17 12:22:00 +01:00
|
|
|
<para>
|
|
|
|
Other parameters are sufficiently sized for any application.
|
|
|
|
If you want to see for yourself look into
|
2000-07-22 16:49:01 +02:00
|
|
|
<filename>/usr/src/linux/include/asm-<replaceable>xxx</>/shmparam.h</>
|
2000-12-17 12:22:00 +01:00
|
|
|
and <filename>/usr/src/linux/include/linux/sem.h</>.
|
2000-07-22 16:49:01 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>SCO OpenServer</>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
In the default configuration, only 512 kB of shared memory per
|
|
|
|
segment is allowed, which is about enough for <option>-B 24 -N
|
|
|
|
12</>. To increase the setting, first change the directory to
|
|
|
|
<filename>/etc/conf/cf.d</>. To display the current value of
|
|
|
|
<varname>SHMMAX</>, in bytes, run
|
|
|
|
<programlisting>
|
|
|
|
./configure -y SHMMAX
|
|
|
|
</programlisting>
|
|
|
|
To set a new value for <varname>SHMMAX</>, run:
|
|
|
|
<programlisting>
|
|
|
|
./configure SHMMAX=<replaceable>value</>
|
|
|
|
</programlisting>
|
|
|
|
where <replaceable>value</> is the new value you want to use
|
|
|
|
(in bytes). After setting <varname>SHMMAX</>, rebuild the kernel
|
|
|
|
<programlisting>
|
|
|
|
./link_unix
|
|
|
|
</programlisting>
|
|
|
|
and reboot.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>Solaris</>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
At least in version 2.6, the maximum size of a shared memory
|
|
|
|
segment is set too low for <productname>Postgres</>. The
|
|
|
|
relevant settings can be changed in <filename>/etc/system</>,
|
|
|
|
for example:
|
|
|
|
<programlisting>
|
|
|
|
set shmsys:shminfo_shmmax=0x2000000
|
|
|
|
set shmsys:shminfo_shmmin=1
|
|
|
|
set shmsys:shminfo_shmmni=256
|
|
|
|
set shmsys:shminfo_shmseg=256
|
|
|
|
|
|
|
|
set semsys:seminfo_semmap=256
|
|
|
|
set semsys:seminfo_semmni=512
|
|
|
|
set semsys:seminfo_semmns=512
|
|
|
|
set semsys:seminfo_semmsl=32
|
|
|
|
</programlisting>
|
|
|
|
You need to reboot to make the changes effective.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
See also <ulink
|
|
|
|
url="http://www.sunworld.com/swol-09-1997/swol-09-insidesolaris.html">http://www.sunworld.com/swol-09-1997/swol-09-insidesolaris.html</>
|
|
|
|
for information on shared memory under
|
|
|
|
<productname>Solaris</>.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>UnixWare</>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
On <productname>UnixWare</> 7, the maximum size for shared
|
|
|
|
memory segments is 512 kB in the default configuration. This
|
|
|
|
is enough for about <option>-B 24 -N 12</>. To display the
|
|
|
|
current value of <varname>SHMMAX</>, run
|
|
|
|
<programlisting>
|
|
|
|
/etc/conf/bin/idtune -g SHMMAX
|
|
|
|
</programlisting>
|
|
|
|
which displays the current, default, minimum, and maximum
|
|
|
|
values, in bytes. To set a new value for <varname>SHMMAX</>,
|
|
|
|
run:
|
|
|
|
<programlisting>
|
|
|
|
/etc/conf/bin/idtune SHMMAX <replaceable>value</>
|
|
|
|
</programlisting>
|
|
|
|
where <replaceable>value</> is the new value you want to use
|
|
|
|
(in bytes). After setting <varname>SHMMAX</>, rebuild the
|
|
|
|
kernel
|
|
|
|
<programlisting>
|
|
|
|
/etc/conf/bin/idbuild -B
|
|
|
|
</programlisting>
|
|
|
|
and reboot.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
</variablelist>
|
|
|
|
|
|
|
|
</para>
|
|
|
|
</sect2>
|
|
|
|
|
2001-01-08 22:01:54 +01:00
|
|
|
|
|
|
|
<sect2>
|
|
|
|
<title>Resource Limits</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Unix-like operating systems enforce various kinds of resource
|
|
|
|
limits that might interfere with the operation of your
|
|
|
|
<productname>Postgres</productname> server. Of importance are
|
|
|
|
especially the limits on the number of processes per user, the
|
|
|
|
number of open files per process, and the amount of memory
|
|
|
|
available to a process. Each of these have a <quote>hard</quote>
|
|
|
|
and a <quote>soft</quote> limit. The soft limit is what actually
|
|
|
|
counts but it can be changed by the user up to the hard limit.
|
|
|
|
The hard limit can only be changed by the root user. The system
|
|
|
|
call <function>setrlimit</function> is responsible for setting
|
|
|
|
these parameters. The shell the built-in command
|
|
|
|
<command>ulimit</command> (Bourne shells) or
|
|
|
|
<command>limit</command> (csh) is used to control the resource
|
|
|
|
limits from the command line. On BSD-derived systems the file
|
|
|
|
<filename>/etc/login.conf</filename> controls what values the
|
|
|
|
various resource limits are set to upon login. See
|
|
|
|
<citerefentry><refentrytitle>login.conf</refentrytitle>
|
|
|
|
<manvolnum>5</manvolnum></citerefentry> for details. The relevant
|
|
|
|
parameters are <varname>maxproc</varname>,
|
|
|
|
<varname>openfiles</varname>, and <varname>datasize</varname>.
|
|
|
|
For example:
|
|
|
|
<programlisting>
|
|
|
|
default:\
|
|
|
|
...
|
|
|
|
:datasize-cur=256M:\
|
|
|
|
:maxproc-cur=256:\
|
|
|
|
:openfiles-cur=256:\
|
|
|
|
...
|
|
|
|
</programlisting>
|
|
|
|
(<literal>-cur</literal> is the soft limit. Append
|
|
|
|
<literal>-max</literal> to set the hard limit.)
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Kernels generally also have an implementation-dependent
|
|
|
|
system-wide limit on some resources.
|
2001-02-09 21:38:15 +01:00
|
|
|
<itemizedlist>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
2001-01-08 22:01:54 +01:00
|
|
|
On <productname>Linux</productname>
|
|
|
|
<filename>/proc/sys/fs/file-max</filename> determines the
|
|
|
|
maximum number of files that the kernel will allocate. It can
|
|
|
|
be changed by writing a different number into the file or by
|
|
|
|
adding an assignment in <filename>/etc/sysctl.conf</filename>.
|
|
|
|
The maximum limit of files per process is fixed at the time the
|
|
|
|
kernel is compiled; see
|
|
|
|
<filename>/usr/src/linux/Documentation/proc.txt</filename> for
|
|
|
|
more information.
|
2001-02-09 21:38:15 +01:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</itemizedlist>
|
2001-01-08 22:01:54 +01:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The <productname>Postgres</productname> server uses one process
|
|
|
|
per connection so you should provide for at least as many processes
|
|
|
|
as allowed connections, in addition to what you need for the rest
|
|
|
|
of your system. This is usually not a problem but if you run
|
|
|
|
several servers on one machine things might get tight.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The factory default limit on open files is often set to
|
|
|
|
<quote>socially friendly</quote> values that allow many users to
|
|
|
|
coexist on a machine without using an inappropriate fraction of
|
|
|
|
the system resources. If you run many servers on a machine this
|
|
|
|
is perhaps what you want, but on dedicated servers you may want to
|
|
|
|
raise this limit.
|
|
|
|
</para>
|
|
|
|
</sect2>
|
2000-07-22 16:49:01 +02:00
|
|
|
|
|
|
|
</sect1>
|
|
|
|
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
<sect1 id="postmaster-shutdown">
|
|
|
|
<title>Shutting down the server</title>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Depending on your needs, there are several ways to shut down the
|
|
|
|
database server when your work is done. The differentiation is
|
|
|
|
done by what signal you send to the server process.
|
|
|
|
<variablelist>
|
|
|
|
<varlistentry>
|
|
|
|
<term>SIGTERM</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
After receiving SIGTERM, the postmaster disallows new
|
|
|
|
connections but lets active backend end their work and shuts
|
|
|
|
down only after all of them terminated (by client request).
|
|
|
|
This is the <firstterm>Smart Shutdown</firstterm>.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>SIGINT</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
The postmaster disallows new connections, sends all active
|
|
|
|
backends SIGTERM (which will cause them to abort immediately),
|
|
|
|
waits for children to exit and shuts down the data base. This
|
|
|
|
is the <firstterm>Fast Shutdown</firstterm>.
|
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
|
|
|
|
<varlistentry>
|
|
|
|
<term>SIGQUIT</term>
|
|
|
|
<listitem>
|
|
|
|
<para>
|
|
|
|
This is the <firstterm>Immediate Shutdown</firstterm> which
|
XLOG (and related) changes:
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
2001-03-13 02:17:06 +01:00
|
|
|
will cause the postmaster to send a SIGQUIT to all backends and
|
2000-06-18 23:24:54 +02:00
|
|
|
exit immediately (without properly shutting down the database
|
|
|
|
system). When WAL is implemented, this will lead to recovery on
|
2000-08-29 22:02:09 +02:00
|
|
|
start-up. Right now it's not recommendable to use this option.
|
2000-06-18 23:24:54 +02:00
|
|
|
</para>
|
|
|
|
</listitem>
|
|
|
|
</varlistentry>
|
|
|
|
</variablelist>
|
|
|
|
|
|
|
|
<caution>
|
|
|
|
<para>
|
|
|
|
If at all possible, do not use SIGKILL to shut down the
|
|
|
|
postmaster. This can cause data corruption and will prevent the
|
|
|
|
cleaning up of shared memory resources, which you will have to
|
|
|
|
do yourself in that case.
|
|
|
|
</para>
|
|
|
|
</caution>
|
|
|
|
|
|
|
|
The PID of the postmaster process can be found using the
|
|
|
|
<application>ps</application> program, or from the file
|
|
|
|
<filename>postmaster.pid</filename> in the data directory. So for
|
|
|
|
example, to do a fast shutdown:
|
|
|
|
<screen>
|
|
|
|
> <userinput>kill -INT `cat /usr/local/pgsql/data/postmaster.pid`</userinput>
|
|
|
|
</screen>
|
|
|
|
</para>
|
|
|
|
<para>
|
|
|
|
The program <application>pg_ctl</application> is a shell script
|
|
|
|
wrapper that provides a convenient interface to these functions.
|
|
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
2000-10-20 16:00:49 +02:00
|
|
|
<sect1 id="ssl-tcp">
|
2000-09-06 21:54:52 +02:00
|
|
|
<title>Secure TCP/IP Connections with SSL</title>
|
2000-08-29 06:15:43 +02:00
|
|
|
|
|
|
|
<para>
|
2000-09-06 21:54:52 +02:00
|
|
|
<productname>PostgreSQL</> has native support for connections over
|
|
|
|
<acronym>SSL</> to encrypt
|
2000-08-29 06:15:43 +02:00
|
|
|
client/server communications for increased security. This requires
|
|
|
|
<productname>OpenSSL</productname> to be installed on both client
|
2000-09-06 21:54:52 +02:00
|
|
|
and server systems and support enabled at build-time (see <xref
|
|
|
|
linkend="installation">).
|
2000-08-29 06:15:43 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2000-09-06 21:54:52 +02:00
|
|
|
With SSL support compiled in, the <productname>PostgreSQL</> server
|
|
|
|
can be started with the argument <option>-l</> (ell) to enable
|
|
|
|
SSL connections. When starting in SSL mode, the postmaster will look
|
|
|
|
for the files <filename>server.key</> and <filename>server.crt</> in
|
2001-01-08 22:01:54 +01:00
|
|
|
the data directory. These files should contain the server private key
|
2000-09-06 21:54:52 +02:00
|
|
|
and certificate respectively. These files must be set up correctly
|
|
|
|
before an SSL-enabled server can start. If the private key is protected
|
|
|
|
with a passphrase, the postmaster will prompt for the passphrase and will
|
2001-01-08 22:01:54 +01:00
|
|
|
not start until it has been entered.
|
2000-08-29 06:15:43 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The postmaster will listen for both standard and SSL connections
|
|
|
|
on the same TCP/IP port, and will negotiate with any connecting
|
2000-10-20 16:00:49 +02:00
|
|
|
client whether or not to use SSL.
|
2001-01-08 22:01:54 +01:00
|
|
|
See <xref linkend="client-authentication">
|
2000-09-06 21:54:52 +02:00
|
|
|
about how to force on the server side the use of SSL for certain
|
|
|
|
connections.
|
2000-08-29 06:15:43 +02:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
For details on how to create your server private key and certificate,
|
2000-09-06 21:54:52 +02:00
|
|
|
refer to the <productname>OpenSSL</> documentation. A simple self-signed
|
2000-12-21 20:08:05 +01:00
|
|
|
certificate can be used to get started for testing, but a certificate signed
|
2000-09-06 21:54:52 +02:00
|
|
|
by a CA (either one of the global CAs or a local one) should be used in
|
2000-08-29 06:15:43 +02:00
|
|
|
production so the client can verify the servers identity. To create
|
2000-12-21 20:08:05 +01:00
|
|
|
a quick self-signed certificate, use the following OpenSSL command:
|
2001-01-08 22:01:54 +01:00
|
|
|
<programlisting>
|
|
|
|
openssl req -new -text -out cert.req
|
|
|
|
</programlisting>
|
2000-12-21 20:08:05 +01:00
|
|
|
Fill out the information that openssl asks for. Make sure that you enter
|
|
|
|
the local host name as Common Name; the challenge password can be
|
2001-01-08 22:01:54 +01:00
|
|
|
left blank. The script will generate a key that is passphrase protected;
|
|
|
|
it will not accept a pass phrase that is less than four characters long.
|
|
|
|
To remove the passphrase (as you must if you want automatic start-up of
|
|
|
|
the postmaster), run the commands
|
|
|
|
<programlisting>
|
2001-01-24 16:19:36 +01:00
|
|
|
openssl rsa -in privkey.pem -out cert.pem
|
2001-01-08 22:01:54 +01:00
|
|
|
</programlisting>
|
2000-12-21 20:08:05 +01:00
|
|
|
Enter the old passphrase to unlock the existing key. Now do
|
2001-01-08 22:01:54 +01:00
|
|
|
<programlisting>
|
|
|
|
openssl req -x509 -in cert.req -text -key cert.pem -out cert.cert
|
|
|
|
cp cert.pem <replaceable>$PGDATA</replaceable>/server.key
|
|
|
|
cp cert.cert <replaceable>$PGDATA</replaceable>/server.crt
|
|
|
|
</programlisting>
|
2000-12-21 20:08:05 +01:00
|
|
|
to turn the certificate into a self-signed certificate and to copy the
|
2001-01-08 22:01:54 +01:00
|
|
|
key and certificate to where the postmaster will look for them.
|
2000-08-29 06:15:43 +02:00
|
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
2000-10-20 16:00:49 +02:00
|
|
|
<sect1 id="ssh-tunnels">
|
2000-09-06 21:54:52 +02:00
|
|
|
<title>Secure TCP/IP Connections with SSH tunnels</title>
|
2000-06-18 23:24:54 +02:00
|
|
|
|
|
|
|
<note>
|
|
|
|
<title>Acknowledgement</title>
|
|
|
|
<para>
|
|
|
|
Idea taken from an email by Gene Selkov, Jr.
|
|
|
|
(<email>selkovjr@mcs.anl.gov</>) written on 1999-09-08 in response
|
|
|
|
to a question from Eric Marsden.
|
|
|
|
</para>
|
|
|
|
</note>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
One can use <productname>ssh</productname> to encrypt the network
|
|
|
|
connection between clients and a
|
|
|
|
<productname>Postgres</productname> server. Done properly, this
|
|
|
|
should lead to an adequately secure network connection.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
First make sure that an <productname>ssh</productname> server is
|
|
|
|
running properly on the same machine as
|
|
|
|
<productname>Postgres</productname> and that you can log in using
|
|
|
|
ssh as some user. Then you can establish a secure tunnel with a
|
|
|
|
command like this from the client machine:
|
|
|
|
<programlisting>
|
|
|
|
> <userinput>ssh -L 3333:foo.com:5432 joe@foo.com</userinput>
|
|
|
|
</programlisting>
|
|
|
|
The first number in the <option>-L</option> argument, 3333, is the
|
|
|
|
port number of your end of the tunnel; it can be chosen freely. The
|
|
|
|
second number, 5432, is the remote end of the tunnel -- the port
|
|
|
|
number your backend is using. The name or the address in between
|
|
|
|
the port numbers is the host with the database server you are going
|
|
|
|
to connect to. In order to connect to the database server using
|
|
|
|
this tunnel, you connect to port 3333 on the local machine:
|
|
|
|
<programlisting>
|
|
|
|
psql -h localhost -p 3333 template1
|
|
|
|
</programlisting>
|
|
|
|
To the database server it will then look as though you are really
|
|
|
|
user <literal>joe@foo.com</literal> and it will use whatever
|
|
|
|
authentication procedure was set up for this user. In order for the
|
|
|
|
tunnel setup to succeed you must be allowed to connect via ssh as
|
|
|
|
joe@foo.com, just as if you had attempted to use ssh to set up a
|
|
|
|
terminal session.
|
|
|
|
</para>
|
|
|
|
|
2000-09-06 21:54:52 +02:00
|
|
|
<tip>
|
|
|
|
<para>
|
|
|
|
Several other products exist that can provide secure tunnels using
|
|
|
|
a procedure similar in concept to the one just described.
|
|
|
|
</para>
|
|
|
|
</tip>
|
|
|
|
|
2000-06-18 23:24:54 +02:00
|
|
|
</sect1>
|
1998-09-30 07:41:54 +02:00
|
|
|
|
|
|
|
</Chapter>
|
1999-05-20 07:39:29 +02:00
|
|
|
|
|
|
|
<!-- Keep this comment at the end of the file
|
|
|
|
Local variables:
|
2000-03-31 05:27:42 +02:00
|
|
|
mode:sgml
|
1999-05-20 07:39:29 +02:00
|
|
|
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
|
2000-03-31 05:27:42 +02:00
|
|
|
sgml-local-catalogs:("/usr/lib/sgml/catalog")
|
1999-05-20 07:39:29 +02:00
|
|
|
sgml-local-ecat-files:nil
|
|
|
|
End:
|
|
|
|
-->
|