+=head2 Plugin C<postgresql>
+
+The C<postgresql> plugin queries statistics from PostgreSQL databases. It
+keeps a persistent connection to all configured databases and tries to
+reconnect if the connection has been interrupted. The statistics are collected
+from PostgreSQL's B<statistics collector> which thus has to be enabled for
+this plugin to work correctly. This should usually be the case by default.
+See the section "The Statistics Collector" of the B<PostgreSQL Documentation>
+for details.
+
+The B<PostgreSQL Documentation> manual can be found at
+L<http://www.postgresql.org/docs/manuals/>.
+
+ <Plugin postgresql>
+ <Database foo>
+ Host "hostname"
+ Port "5432"
+ User "username"
+ Password "secret"
+ SSLMode "prefer"
+ KRBSrvName "kerberos_service_name"
+ </Database>
+ <Database bar>
+ Service "service_name"
+ </Database>
+ </Plugin>
+
+=over 4
+
+=item B<Database> block
+
+The B<Database> block defines one PostgreSQL database for which to collect
+statistics. It accepts a single mandatory argument which specifies the
+database name. None of the other options are required. PostgreSQL will use
+default values as documented in the section "CONNECTING TO A DATABASE" in the
+L<psql(1)> manpage. However, be aware that those defaults may be influenced by
+the user collectd is run as and special environment variables. See the manpage
+for details.
+
+=item B<Host> I<hostname>
+
+Specify the hostname or IP of the PostgreSQL server to connect to. If the
+value begins with a slash, it is interpreted as the directory name in which to
+look for the UNIX domain socket.
+
+This option is also used to determine the hostname that is associated with a
+collected data set. If it has been omitted or either begins with with a slash
+or equals B<localhost> it will be replaced with the global hostname definition
+of collectd. Any other value will be passed literally to collectd when
+dispatching values. Also see the global B<Hostname> and B<FQDNLookup> options.
+
+=item B<Port> I<port>
+
+Specify the TCP port or the local UNIX domain socket file extension of the
+server.
+
+=item B<User> I<username>
+
+Specify the username to be used when connecting to the server.
+
+=item B<Password> I<password>
+
+Specify the password to be used when connecting to the server.
+
+=item B<SSLMode> I<disable>|I<allow>|I<prefer>|I<require>
+
+Specify whether to use an SSL connection when contacting the server. The
+following modes are supported:
+
+=over 4
+
+=item I<disable>
+
+Do not use SSL at all.
+
+=item I<allow>
+
+First, try to connect without using SSL. If that fails, try using SSL.
+
+=item I<prefer> (default)
+
+First, try to connect using SSL. If that fails, try without using SSL.
+
+=item I<require>
+
+Use SSL only.
+
+=back
+
+=item B<KRBSrvName> I<kerberos_service_name>
+
+Specify the Kerberos service name to use when authenticating with Kerberos 5
+or GSSAPI. See the sections "Kerberos authentication" and "GSSAPI" of the
+B<PostgreSQL Documentation> for details.
+
+=item B<Service> I<service_name>
+
+Specify the PostgreSQL service name to use for additional parameters. That
+service has to be defined in F<pg_service.conf> and holds additional
+connection parameters. See the section "The Connection Service File" in the
+B<PostgreSQL Documentation> for details.
+
+=back
+
+=head2 Plugin C<powerdns>
+
+The C<powerdns> plugin queries statistics from an authoritative PowerDNS
+nameserver and/or a PowerDNS recursor. Since both offer a wide variety of
+values, many of which are probably meaningless to most users, but may be useful
+for some. So you may chose which values to collect, but if you don't, some
+reasonable defaults will be collected.
+
+ <Plugin "powerdns">
+ <Server "server_name">
+ Collect "latency"
+ Collect "udp-answers" "udp-queries"
+ Socket "/var/run/pdns.controlsocket"
+ </Server>
+ <Recursor "recursor_name">
+ Collect "questions"
+ Collect "cache-hits" "cache-misses"
+ Socket "/var/run/pdns_recursor.controlsocket"
+ </Recursor>
+ LocalSocket "/opt/collectd/var/run/collectd-powerdns"
+ </Plugin>
+
+=over 4
+
+=item B<Server> and B<Recursor> block
+
+The B<Server> block defines one authoritative server to query, the B<Recursor>
+does the same for an recursing server. The possible options in both blocks are
+the same, though. The argument defines a name for the serverE<nbsp>/ recursor
+and is required.
+
+=over 4
+
+=item B<Collect> I<Field>
+
+Using the B<Collect> statement you can select which values to collect. Here,
+you specify the name of the values as used by the PowerDNS servers, e.E<nbsp>g.
+C<dlg-only-drops>, C<answers10-100>.
+
+The method of getting the values differs for B<Server> and B<Recursor> blocks:
+When querying the server a C<SHOW *> command is issued in any case, because
+that's the only way of getting multiple values out of the server at once.
+collectd then picks out the values you have selected. When querying the
+recursor, a command is generated to query exactly these values. So if you
+specify invalid fields when querying the recursor, a syntax error may be
+returned by the daemon and collectd may not collect any values at all.
+
+If no B<Collect> statement is given, the following B<Server> values will be
+collected:
+
+=over 4
+
+=item latency
+
+=item packetcache-hit
+
+=item packetcache-miss
+
+=item packetcache-size
+
+=item query-cache-hit
+
+=item query-cache-miss
+
+=item recursing-answers
+
+=item recursing-questions
+
+=item tcp-answers
+
+=item tcp-queries
+
+=item udp-answers
+
+=item udp-queries
+
+=back
+
+The following B<Recursor> values will be collected by default:
+
+=over 4
+
+=item noerror-answers
+
+=item nxdomain-answers
+
+=item servfail-answers
+
+=item sys-msec
+
+=item user-msec
+
+=item qa-latency
+
+=item cache-entries
+
+=item cache-hits
+
+=item cache-misses
+
+=item questions
+
+=back
+
+Please note that up to that point collectd doesn't know what values are
+available on the server and values that are added do not need a change of the
+mechanism so far. However, the values must be mapped to collectd's naming
+scheme, which is done using a lookup table that lists all known values. If
+values are added in the future and collectd does not know about them, you will
+get an error much like this:
+
+ powerdns plugin: submit: Not found in lookup table: foobar = 42
+
+In this case please file a bug report with the collectd team.
+
+=item B<Socket> I<Path>
+
+Configures the path to the UNIX domain socket to be used when connecting to the
+daemon. By default C</var/run/pdns.controlsocket> will be used for an
+authoritative server and C</var/run/pdns_recursor.controlsocket> will be used
+for the recursor.
+
+=back
+
+=item B<LocalSocket> I<Path>
+
+Querying the recursor is done using UDP. When using UDP over UNIX domain
+sockets, the client socket needs a name in the file system, too. You can set
+this local name to I<Path> using the B<LocalSocket> option. The default is
+C<I<prefix>/var/run/collectd-powerdns>.
+
+=back
+