19.8.1. Where To Log log_destination (string) PostgreSQL supports several methods for logging server messages, including stderr, csvlog and syslog. On Windows, eventlog is also supported. Set this parameter to a list of desired log destinations separated by commas. The default is to log to stderr only. This parameter can only be set in the postgresql.conf file or on the server command line. If csvlog is included in log_destination, log entries are output in "comma separated value" (CSV) for

NameDROP AGGREGATE -- remove an aggregate function Synopsis DROP AGGREGATE [ IF EXISTS ] name ( aggregate_signature ) [ CASCADE | RESTRICT ] where aggregate_signature is: * | [ argmode ] [ argname ] argtype [ , ... ] | [ [ argmode ] [ argname ] argtype [ , ... ] ] ORDER BY [ argmode ] [ argname ] argtype [ , ... ] Description DROP AGGREGATE removes an existing aggregate function. To execute this command the current user must be the owner of the aggregate function. Parameters IF

If the primary server fails then the standby server should begin failover procedures. If the standby server fails then no failover need take place. If the standby server can be restarted, even some time later, then the recovery process can also be restarted immediately, taking advantage of restartable recovery. If the standby server cannot be restarted, then a full new standby server instance should be created. If the primary server fails and the standby server becomes the new primary, and then

NameCOPY -- copy data between a file and a table Synopsis COPY table_name [ ( column_name [, ...] ) ] FROM { 'filename' | PROGRAM 'command' | STDIN } [ [ WITH ] ( option [, ...] ) ] COPY { table_name [ ( column_name [, ...] ) ] | ( query ) } TO { 'filename' | PROGRAM 'command' | STDOUT } [ [ WITH ] ( option [, ...] ) ] where option can be one of: FORMAT format_name OIDS [ boolean ] FREEZE [ boolean ] DELIMITER 'delimiter_character' NULL 'null_string'

The view pg_locks provides access to information about the locks held by active processes within the database server. See Chapter 13 for more discussion of locking. pg_locks contains one row per active lockable object, requested lock mode, and relevant process. Thus, the same lockable object might appear many times, if multiple processes are holding or waiting for locks on it. However, an object that currently has no locks on it will not appear at all. There are several distinct types of lockab

This section describes functions and operators for examining and manipulating string values. Strings in this context include values of the types character, character varying, and text. Unless otherwise noted, all of the functions listed below work on all of these types, but be wary of potential effects of automatic space-padding when using the character type. Some functions also exist natively for the bit-string types. SQL defines some string functions that use key words, rather than commas, to

This section describes the SQL-compliant conditional expressions available in PostgreSQL. Tip: If your needs go beyond the capabilities of these conditional expressions, you might want to consider writing a stored procedure in a more expressive programming language. 9.17.1. CASE The SQL CASE expression is a generic conditional expression, similar to if/else statements in other programming languages: CASE WHEN condition THEN result [WHEN ...] [ELSE result] END CASE clauses can

Namepg_dump -- extract a PostgreSQL database into a script file or other archive file Synopsis pg_dump [connection-option...] [option...] [dbname] Description pg_dump is a utility for backing up a PostgreSQL database. It makes consistent backups even if the database is being used concurrently. pg_dump does not block other users accessing the database (readers or writers). pg_dump only dumps a single database. To backup global objects that are common to all databases in a cluster, such a

The catalog pg_user_mapping stores the mappings from local user to remote. Access to this catalog is restricted from normal users, use the view pg_user_mappings instead. Table 50-57. pg_user_mapping Columns Name Type References Description oid oid Row identifier (hidden attribute; must be explicitly selected) umuser oid pg_authid.oid OID of the local role being mapped, 0 if the user mapping is public umserver oid pg_foreign_server.oid The OID of the foreign server that contains this mapping

In addition to the system catalogs, PostgreSQL provides a number of built-in views. Some system views provide convenient access to some commonly used queries on the system catalogs. Other views provide access to internal server state. The information schema (Chapter 35) provides an alternative set of views which overlap the functionality of the system views. Since the information schema is SQL-standard whereas the views described here are PostgreSQL-specific, it's usually better to use the info