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man : psql(1)

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PSQL(1)                                          PostgreSQL 9.4.3 Documentation                                          PSQL(1)



NAME
       psql - PostgreSQL interactive terminal

SYNOPSIS
       psql [option...] [dbname [username]]

DESCRIPTION
       psql is a terminal-based front-end to PostgreSQL. It enables you to type in queries interactively, issue them to
       PostgreSQL, and see the query results. Alternatively, input can be from a file. In addition, it provides a number of
       meta-commands and various shell-like features to facilitate writing scripts and automating a wide variety of tasks.

OPTIONS
       -a
       --echo-all
           Print all nonempty input lines to standard output as they are read. (This does not apply to lines read
           interactively.) This is equivalent to setting the variable ECHO to all.

       -A
       --no-align
           Switches to unaligned output mode. (The default output mode is otherwise aligned.)

       -c command
       --command=command
           Specifies that psql is to execute one command string, command, and then exit. This is useful in shell scripts.
           Start-up files (psqlrc and ~/.psqlrc) are ignored with this option.


           command must be either a command string that is completely parsable by the server (i.e., it contains no psql-specific
           features), or a single backslash command. Thus you cannot mix SQL and psql meta-commands with this option. To achieve
           that, you could pipe the string into psql, for example: echo '\x \\ SELECT * FROM foo;' | psql. (\\ is the separator
           meta-command.)

           If the command string contains multiple SQL commands, they are processed in a single transaction, unless there are
           explicit BEGIN/COMMIT commands included in the string to divide it into multiple transactions. This is different from
           the behavior when the same string is fed to psql's standard input. Also, only the result of the last SQL command is
           returned.

           Because of these legacy behaviors, putting more than one command in the -c string often has unexpected results. It's
           better to feed multiple commands to psql's standard input, either using echo as illustrated above, or via a shell
           here-document, for example:

               psql <<EOF
               \x
               SELECT * FROM foo;
               EOF


       -d dbname
       --dbname=dbname
           Specifies the name of the database to connect to. This is equivalent to specifying dbname as the first non-option
           argument on the command line.

           If this parameter contains an = sign or starts with a valid URI prefix (postgresql:// or postgres://), it is treated
           as a conninfo string. See Section 31.1.1, "Connection Strings", in the documentation for more information.

       -e
       --echo-queries
           Copy all SQL commands sent to the server to standard output as well. This is equivalent to setting the variable ECHO
           to queries.

       -E
       --echo-hidden
           Echo the actual queries generated by \d and other backslash commands. You can use this to study psql's internal
           operations. This is equivalent to setting the variable ECHO_HIDDEN to on.

       -f filename
       --file=filename
           Use the file filename as the source of commands instead of reading commands interactively. After the file is
           processed, psql terminates. This is in many ways equivalent to the meta-command \i.

           If filename is - (hyphen), then standard input is read.

           Using this option is subtly different from writing psql < filename. In general, both will do what you expect, but
           using -f enables some nice features such as error messages with line numbers. There is also a slight chance that
           using this option will reduce the start-up overhead. On the other hand, the variant using the shell's input
           redirection is (in theory) guaranteed to yield exactly the same output you would have received had you entered
           everything by hand.

       -F separator
       --field-separator=separator
           Use separator as the field separator for unaligned output. This is equivalent to \pset fieldsep or \f.

       -h hostname
       --host=hostname
           Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used
           as the directory for the Unix-domain socket.

       -H
       --html
           Turn on HTML tabular output. This is equivalent to \pset format html or the \H command.

       -l
       --list
           List all available databases, then exit. Other non-connection options are ignored. This is similar to the
           meta-command \list.

       -L filename
       --log-file=filename
           Write all query output into file filename, in addition to the normal output destination.

       -n
       --no-readline
           Do not use Readline for line editing and do not use the command history. This can be useful to turn off tab expansion
           when cutting and pasting.

       -o filename
       --output=filename
           Put all query output into file filename. This is equivalent to the command \o.

       -p port
       --port=port
           Specifies the TCP port or the local Unix-domain socket file extension on which the server is listening for
           connections. Defaults to the value of the PGPORT environment variable or, if not set, to the port specified at
           compile time, usually 5432.

       -P assignment
       --pset=assignment
           Specifies printing options, in the style of \pset. Note that here you have to separate name and value with an equal
           sign instead of a space. For example, to set the output format to LaTeX, you could write -P format=latex.

       -q
       --quiet
           Specifies that psql should do its work quietly. By default, it prints welcome messages and various informational
           output. If this option is used, none of this happens. This is useful with the -c option. This is equivalent to
           setting the variable QUIET to on.

       -R separator
       --record-separator=separator
           Use separator as the record separator for unaligned output. This is equivalent to the \pset recordsep command.

       -s
       --single-step
           Run in single-step mode. That means the user is prompted before each command is sent to the server, with the option
           to cancel execution as well. Use this to debug scripts.

       -S
       --single-line
           Runs in single-line mode where a newline terminates an SQL command, as a semicolon does.

               Note
               This mode is provided for those who insist on it, but you are not necessarily encouraged to use it. In
               particular, if you mix SQL and meta-commands on a line the order of execution might not always be clear to the
               inexperienced user.

       -t
       --tuples-only
           Turn off printing of column names and result row count footers, etc. This is equivalent to the \t command.

       -T table_options
       --table-attr=table_options
           Specifies options to be placed within the HTML table tag. See \pset for details.

       -U username
       --username=username
           Connect to the database as the user username instead of the default. (You must have permission to do so, of course.)

       -v assignment
       --set=assignment
       --variable=assignment
           Perform a variable assignment, like the \set meta-command. Note that you must separate name and value, if any, by an
           equal sign on the command line. To unset a variable, leave off the equal sign. To set a variable with an empty value,
           use the equal sign but leave off the value. These assignments are done during a very early stage of start-up, so
           variables reserved for internal purposes might get overwritten later.

       -V
       --version
           Print the psql version and exit.

       -w
       --no-password
           Never issue a password prompt. If the server requires password authentication and a password is not available by
           other means such as a .pgpass file, the connection attempt will fail. This option can be useful in batch jobs and
           scripts where no user is present to enter a password.

           Note that this option will remain set for the entire session, and so it affects uses of the meta-command \connect as
           well as the initial connection attempt.

       -W
       --password
           Force psql to prompt for a password before connecting to a database.

           This option is never essential, since psql will automatically prompt for a password if the server demands password
           authentication. However, psql will waste a connection attempt finding out that the server wants a password. In some
           cases it is worth typing -W to avoid the extra connection attempt.

           Note that this option will remain set for the entire session, and so it affects uses of the meta-command \connect as
           well as the initial connection attempt.

       -x
       --expanded
           Turn on the expanded table formatting mode. This is equivalent to the \x command.

       -X,
       --no-psqlrc
           Do not read the start-up file (neither the system-wide psqlrc file nor the user's ~/.psqlrc file).

       -z
       --field-separator-zero
           Set the field separator for unaligned output to a zero byte.

       -0
       --record-separator-zero
           Set the record separator for unaligned output to a zero byte. This is useful for interfacing, for example, with xargs
           -0.

       -1
       --single-transaction
           When psql executes a script, adding this option wraps BEGIN/COMMIT around the script to execute it as a single
           transaction. This ensures that either all the commands complete successfully, or no changes are applied.

           If the script itself uses BEGIN, COMMIT, or ROLLBACK, this option will not have the desired effects. Also, if the
           script contains any command that cannot be executed inside a transaction block, specifying this option will cause
           that command (and hence the whole transaction) to fail.

       -?
       --help
           Show help about psql command line arguments, and exit.

EXIT STATUS
       psql returns 0 to the shell if it finished normally, 1 if a fatal error of its own occurs (e.g. out of memory, file not
       found), 2 if the connection to the server went bad and the session was not interactive, and 3 if an error occurred in a
       script and the variable ON_ERROR_STOP was set.

USAGE
   Connecting to a Database
       psql is a regular PostgreSQL client application. In order to connect to a database you need to know the name of your
       target database, the host name and port number of the server, and what user name you want to connect as.  psql can be
       told about those parameters via command line options, namely -d, -h, -p, and -U respectively. If an argument is found
       that does not belong to any option it will be interpreted as the database name (or the user name, if the database name is
       already given). Not all of these options are required; there are useful defaults. If you omit the host name, psql will
       connect via a Unix-domain socket to a server on the local host, or via TCP/IP to localhost on machines that don't have
       Unix-domain sockets. The default port number is determined at compile time. Since the database server uses the same
       default, you will not have to specify the port in most cases. The default user name is your operating-system user name,
       as is the default database name. Note that you cannot just connect to any database under any user name. Your database
       administrator should have informed you about your access rights.

       When the defaults aren't quite right, you can save yourself some typing by setting the environment variables PGDATABASE,
       PGHOST, PGPORT and/or PGUSER to appropriate values. (For additional environment variables, see Section 31.14,
       "Environment Variables", in the documentation.) It is also convenient to have a ~/.pgpass file to avoid regularly having
       to type in passwords. See Section 31.15, "The Password File", in the documentation for more information.

       An alternative way to specify connection parameters is in a conninfo string or a URI, which is used instead of a database
       name. This mechanism give you very wide control over the connection. For example:

           $ psql "service=myservice sslmode=require"
           $ psql postgresql://dbmaster:5433/mydb?sslmode=require

       This way you can also use LDAP for connection parameter lookup as described in Section 31.17, "LDAP Lookup of Connection
       Parameters", in the documentation. See Section 31.1.2, "Parameter Key Words", in the documentation for more information
       on all the available connection options.

       If the connection could not be made for any reason (e.g., insufficient privileges, server is not running on the targeted
       host, etc.), psql will return an error and terminate.

       If both standard input and standard output are a terminal, then psql sets the client encoding to "auto", which will
       detect the appropriate client encoding from the locale settings (LC_CTYPE environment variable on Unix systems). If this
       doesn't work out as expected, the client encoding can be overridden using the environment variable PGCLIENTENCODING.

   Entering SQL Commands
       In normal operation, psql provides a prompt with the name of the database to which psql is currently connected, followed
       by the string =>. For example:

           $ psql testdb
           psql (9.4.3)
           Type "help" for help.

           testdb=>

       At the prompt, the user can type in SQL commands. Ordinarily, input lines are sent to the server when a
       command-terminating semicolon is reached. An end of line does not terminate a command. Thus commands can be spread over
       several lines for clarity. If the command was sent and executed without error, the results of the command are displayed
       on the screen.

       Whenever a command is executed, psql also polls for asynchronous notification events generated by LISTEN(7) and
       NOTIFY(7).

       While C-style block comments are passed to the server for processing and removal, SQL-standard comments are removed by
       psql.

   Meta-Commands
       Anything you enter in psql that begins with an unquoted backslash is a psql meta-command that is processed by psql
       itself. These commands make psql more useful for administration or scripting. Meta-commands are often called slash or
       backslash commands.

       The format of a psql command is the backslash, followed immediately by a command verb, then any arguments. The arguments
       are separated from the command verb and each other by any number of whitespace characters.

       To include whitespace in an argument you can quote it with single quotes. To include a single quote in an argument, write
       two single quotes within single-quoted text. Anything contained in single quotes is furthermore subject to C-like
       substitutions for \n (new line), \t (tab), \b (backspace), \r (carriage return), \f (form feed), \digits (octal), and
       \xdigits (hexadecimal). A backslash preceding any other character within single-quoted text quotes that single character,
       whatever it is.

       Within an argument, text that is enclosed in backquotes (`) is taken as a command line that is passed to the shell. The
       output of the command (with any trailing newline removed) replaces the backquoted text.

       If an unquoted colon (:) followed by a psql variable name appears within an argument, it is replaced by the variable's
       value, as described in SQL Interpolation.

       Some commands take an SQL identifier (such as a table name) as argument. These arguments follow the syntax rules of SQL:
       Unquoted letters are forced to lowercase, while double quotes (") protect letters from case conversion and allow
       incorporation of whitespace into the identifier. Within double quotes, paired double quotes reduce to a single double
       quote in the resulting name. For example, FOO"BAR"BAZ is interpreted as fooBARbaz, and "A weird"" name" becomes A weird"
       name.

       Parsing for arguments stops at the end of the line, or when another unquoted backslash is found. An unquoted backslash is
       taken as the beginning of a new meta-command. The special sequence \\ (two backslashes) marks the end of arguments and
       continues parsing SQL commands, if any. That way SQL and psql commands can be freely mixed on a line. But in any case,
       the arguments of a meta-command cannot continue beyond the end of the line.

       The following meta-commands are defined:

       \a
           If the current table output format is unaligned, it is switched to aligned. If it is not unaligned, it is set to
           unaligned. This command is kept for backwards compatibility. See \pset for a more general solution.

       \c or \connect [ dbname [ username ] [ host ] [ port ] ] | conninfo
           Establishes a new connection to a PostgreSQL server. The connection parameters to use can be specified either using a
           positional syntax, or using conninfo connection strings as detailed in Section 31.1.1, "Connection Strings", in the
           documentation.

           When using positional parameters, if any of dbname, username, host or port are omitted or specified as -, the value
           of that parameter from the previous connection is used; if there is no previous connection, the libpq default for the
           parameter's value is used. When using conninfo strings, no values from the previous connection are used for the new
           connection.

           If the new connection is successfully made, the previous connection is closed. If the connection attempt failed
           (wrong user name, access denied, etc.), the previous connection will only be kept if psql is in interactive mode.
           When executing a non-interactive script, processing will immediately stop with an error. This distinction was chosen
           as a user convenience against typos on the one hand, and a safety mechanism that scripts are not accidentally acting
           on the wrong database on the other hand.

           Examples:

               => \c mydb myuser host.dom 6432
               => \c service=foo
               => \c "host=localhost port=5432 dbname=mydb connect_timeout=10 sslmode=disable"
               => \c postgresql://tom@localhost/mydb?application_name=myapp

       \C [ title ]
           Sets the title of any tables being printed as the result of a query or unset any such title. This command is
           equivalent to \pset title title. (The name of this command derives from "caption", as it was previously only used to
           set the caption in an HTML table.)

       \cd [ directory ]
           Changes the current working directory to directory. Without argument, changes to the current user's home directory.

               Tip
               To print your current working directory, use \! pwd.

       \conninfo
           Outputs information about the current database connection.

       \copy { table [ ( column_list ) ] | ( query ) } { from | to } { 'filename' | program 'command' | stdin | stdout | pstdin
       | pstdout } [ [ with ] ( option [, ...] ) ]
           Performs a frontend (client) copy. This is an operation that runs an SQL COPY(7) command, but instead of the server
           reading or writing the specified file, psql reads or writes the file and routes the data between the server and the
           local file system. This means that file accessibility and privileges are those of the local user, not the server, and
           no SQL superuser privileges are required.

           When program is specified, command is executed by psql and the data passed from or to command is routed between the
           server and the client. Again, the execution privileges are those of the local user, not the server, and no SQL
           superuser privileges are required.

           For \copy ... from stdin, data rows are read from the same source that issued the command, continuing until \.  is
           read or the stream reaches EOF. This option is useful for populating tables in-line within a SQL script file. For
           \copy ... to stdout, output is sent to the same place as psql command output, and the COPY count command status is
           not printed (since it might be confused with a data row). To read/write psql's standard input or output regardless of
           the current command source or \o option, write from pstdin or to pstdout.

           The syntax of this command is similar to that of the SQL COPY(7) command. All options other than the data
           source/destination are as specified for COPY(7). Because of this, special parsing rules apply to the \copy command.
           In particular, psql's variable substitution rules and backslash escapes do not apply.

               Tip
               This operation is not as efficient as the SQL COPY command because all data must pass through the client/server
               connection. For large amounts of data the SQL command might be preferable.

       \copyright
           Shows the copyright and distribution terms of PostgreSQL.

       \d[S+] [ pattern ]
           For each relation (table, view, index, sequence, or foreign table) or composite type matching the pattern, show all
           columns, their types, the tablespace (if not the default) and any special attributes such as NOT NULL or defaults.
           Associated indexes, constraints, rules, and triggers are also shown. For foreign tables, the associated foreign
           server is shown as well. ("Matching the pattern" is defined in Patterns below.)

           For some types of relation, \d shows additional information for each column: column values for sequences, indexed
           expression for indexes and foreign data wrapper options for foreign tables.

           The command form \d+ is identical, except that more information is displayed: any comments associated with the
           columns of the table are shown, as is the presence of OIDs in the table, the view definition if the relation is a
           view, a non-default replica identity setting.

           By default, only user-created objects are shown; supply a pattern or the S modifier to include system objects.

               Note
               If \d is used without a pattern argument, it is equivalent to \dtvsE which will show a list of all visible
               tables, views, sequences and foreign tables. This is purely a convenience measure.

       \da[S] [ pattern ]
           Lists aggregate functions, together with their return type and the data types they operate on. If pattern is
           specified, only aggregates whose names match the pattern are shown. By default, only user-created objects are shown;
           supply a pattern or the S modifier to include system objects.

       \db[+] [ pattern ]
           Lists tablespaces. If pattern is specified, only tablespaces whose names match the pattern are shown. If + is
           appended to the command name, each object is listed with its associated permissions.

       \dc[S+] [ pattern ]
           Lists conversions between character-set encodings. If pattern is specified, only conversions whose names match the
           pattern are listed. By default, only user-created objects are shown; supply a pattern or the S modifier to include
           system objects. If + is appended to the command name, each object is listed with its associated description.

       \dC[+] [ pattern ]
           Lists type casts. If pattern is specified, only casts whose source or target types match the pattern are listed. If +
           is appended to the command name, each object is listed with its associated description.

       \dd[S] [ pattern ]
           Shows the descriptions of objects of type constraint, operator class, operator family, rule, and trigger. All other
           comments may be viewed by the respective backslash commands for those object types.

           \dd displays descriptions for objects matching the pattern, or of visible objects of the appropriate type if no
           argument is given. But in either case, only objects that have a description are listed. By default, only user-created
           objects are shown; supply a pattern or the S modifier to include system objects.

           Descriptions for objects can be created with the COMMENT(7) SQL command.

       \ddp [ pattern ]
           Lists default access privilege settings. An entry is shown for each role (and schema, if applicable) for which the
           default privilege settings have been changed from the built-in defaults. If pattern is specified, only entries whose
           role name or schema name matches the pattern are listed.

           The ALTER DEFAULT PRIVILEGES (ALTER_DEFAULT_PRIVILEGES(7)) command is used to set default access privileges. The
           meaning of the privilege display is explained under GRANT(7).

       \dD[S+] [ pattern ]
           Lists domains. If pattern is specified, only domains whose names match the pattern are shown. By default, only
           user-created objects are shown; supply a pattern or the S modifier to include system objects. If + is appended to the
           command name, each object is listed with its associated permissions and description.

       \dE[S+] [ pattern ]
       \di[S+] [ pattern ]
       \dm[S+] [ pattern ]
       \ds[S+] [ pattern ]
       \dt[S+] [ pattern ]
       \dv[S+] [ pattern ]
           In this group of commands, the letters E, i, m, s, t, and v stand for foreign table, index, materialized view,
           sequence, table, and view, respectively. You can specify any or all of these letters, in any order, to obtain a
           listing of objects of these types. For example, \dit lists indexes and tables. If + is appended to the command name,
           each object is listed with its physical size on disk and its associated description, if any. If pattern is specified,
           only objects whose names match the pattern are listed. By default, only user-created objects are shown; supply a
           pattern or the S modifier to include system objects.

       \des[+] [ pattern ]
           Lists foreign servers (mnemonic: "external servers"). If pattern is specified, only those servers whose name matches
           the pattern are listed. If the form \des+ is used, a full description of each server is shown, including the server's
           ACL, type, version, options, and description.

       \det[+] [ pattern ]
           Lists foreign tables (mnemonic: "external tables"). If pattern is specified, only entries whose table name or schema
           name matches the pattern are listed. If the form \det+ is used, generic options and the foreign table description are
           also displayed.

       \deu[+] [ pattern ]
           Lists user mappings (mnemonic: "external users"). If pattern is specified, only those mappings whose user names match
           the pattern are listed. If the form \deu+ is used, additional information about each mapping is shown.

               Caution
               \deu+ might also display the user name and password of the remote user, so care should be taken not to disclose
               them.

       \dew[+] [ pattern ]
           Lists foreign-data wrappers (mnemonic: "external wrappers"). If pattern is specified, only those foreign-data
           wrappers whose name matches the pattern are listed. If the form \dew+ is used, the ACL, options, and description of
           the foreign-data wrapper are also shown.

       \df[antwS+] [ pattern ]
           Lists functions, together with their arguments, return types, and function types, which are classified as "agg"
           (aggregate), "normal", "trigger", or "window". To display only functions of specific type(s), add the corresponding
           letters a, n, t, or w to the command. If pattern is specified, only functions whose names match the pattern are
           shown. By default, only user-created objects are shown; supply a pattern or the S modifier to include system objects.
           If the form \df+ is used, additional information about each function is shown, including security classification,
           volatility, owner, language, source code and description.

               Tip
               To look up functions taking arguments or returning values of a specific type, use your pager's search capability
               to scroll through the \df output.

       \dF[+] [ pattern ]
           Lists text search configurations. If pattern is specified, only configurations whose names match the pattern are
           shown. If the form \dF+ is used, a full description of each configuration is shown, including the underlying text
           search parser and the dictionary list for each parser token type.

       \dFd[+] [ pattern ]
           Lists text search dictionaries. If pattern is specified, only dictionaries whose names match the pattern are shown.
           If the form \dFd+ is used, additional information is shown about each selected dictionary, including the underlying
           text search template and the option values.

       \dFp[+] [ pattern ]
           Lists text search parsers. If pattern is specified, only parsers whose names match the pattern are shown. If the form
           \dFp+ is used, a full description of each parser is shown, including the underlying functions and the list of
           recognized token types.

       \dFt[+] [ pattern ]
           Lists text search templates. If pattern is specified, only templates whose names match the pattern are shown. If the
           form \dFt+ is used, additional information is shown about each template, including the underlying function names.

       \dg[+] [ pattern ]
           Lists database roles. (Since the concepts of "users" and "groups" have been unified into "roles", this command is now
           equivalent to \du.) If pattern is specified, only those roles whose names match the pattern are listed. If the form
           \dg+ is used, additional information is shown about each role; currently this adds the comment for each role.

       \dl
           This is an alias for \lo_list, which shows a list of large objects.

       \dL[S+] [ pattern ]
           Lists procedural languages. If pattern is specified, only languages whose names match the pattern are listed. By
           default, only user-created languages are shown; supply the S modifier to include system objects. If + is appended to
           the command name, each language is listed with its call handler, validator, access privileges, and whether it is a
           system object.

       \dn[S+] [ pattern ]
           Lists schemas (namespaces). If pattern is specified, only schemas whose names match the pattern are listed. By
           default, only user-created objects are shown; supply a pattern or the S modifier to include system objects. If + is
           appended to the command name, each object is listed with its associated permissions and description, if any.

       \do[S+] [ pattern ]
           Lists operators with their operand and result types. If pattern is specified, only operators whose names match the
           pattern are listed. By default, only user-created objects are shown; supply a pattern or the S modifier to include
           system objects. If + is appended to the command name, additional information about each operator is shown, currently
           just the name of the underlying function.

       \dO[S+] [ pattern ]
           Lists collations. If pattern is specified, only collations whose names match the pattern are listed. By default, only
           user-created objects are shown; supply a pattern or the S modifier to include system objects. If + is appended to the
           command name, each collation is listed with its associated description, if any. Note that only collations usable with
           the current database's encoding are shown, so the results may vary in different databases of the same installation.

       \dp [ pattern ]
           Lists tables, views and sequences with their associated access privileges. If pattern is specified, only tables,
           views and sequences whose names match the pattern are listed.

           The GRANT(7) and REVOKE(7) commands are used to set access privileges. The meaning of the privilege display is
           explained under GRANT(7).

       \drds [ role-pattern [ database-pattern ] ]
           Lists defined configuration settings. These settings can be role-specific, database-specific, or both.  role-pattern
           and database-pattern are used to select specific roles and databases to list, respectively. If omitted, or if * is
           specified, all settings are listed, including those not role-specific or database-specific, respectively.

           The ALTER ROLE (ALTER_ROLE(7)) and ALTER DATABASE (ALTER_DATABASE(7)) commands are used to define per-role and
           per-database configuration settings.

       \dT[S+] [ pattern ]
           Lists data types. If pattern is specified, only types whose names match the pattern are listed. If + is appended to
           the command name, each type is listed with its internal name and size, its allowed values if it is an enum type, and
           its associated permissions. By default, only user-created objects are shown; supply a pattern or the S modifier to
           include system objects.

       \du[+] [ pattern ]
           Lists database roles. (Since the concepts of "users" and "groups" have been unified into "roles", this command is now
           equivalent to \dg.) If pattern is specified, only those roles whose names match the pattern are listed. If the form
           \du+ is used, additional information is shown about each role; currently this adds the comment for each role.

       \dx[+] [ pattern ]
           Lists installed extensions. If pattern is specified, only those extensions whose names match the pattern are listed.
           If the form \dx+ is used, all the objects belonging to each matching extension are listed.

       \dy[+] [ pattern ]
           Lists event triggers. If pattern is specified, only those event triggers whose names match the pattern are listed. If
           + is appended to the command name, each object is listed with its associated description.

       \e or \edit [ filename ] [ line_number ]
           If filename is specified, the file is edited; after the editor exits, its content is copied back to the query buffer.
           If no filename is given, the current query buffer is copied to a temporary file which is then edited in the same
           fashion.

           The new query buffer is then re-parsed according to the normal rules of psql, where the whole buffer is treated as a
           single line. (Thus you cannot make scripts this way. Use \i for that.) This means that if the query ends with (or
           contains) a semicolon, it is immediately executed. Otherwise it will merely wait in the query buffer; type semicolon
           or \g to send it, or \r to cancel.

           If a line number is specified, psql will position the cursor on the specified line of the file or query buffer. Note
           that if a single all-digits argument is given, psql assumes it is a line number, not a file name.

               Tip
               See under ENVIRONMENT for how to configure and customize your editor.

       \echo text [ ... ]
           Prints the arguments to the standard output, separated by one space and followed by a newline. This can be useful to
           intersperse information in the output of scripts. For example:

               => \echo `date`
               Tue Oct 26 21:40:57 CEST 1999

           If the first argument is an unquoted -n the trailing newline is not written.

               Tip
               If you use the \o command to redirect your query output you might wish to use \qecho instead of this command.

       \ef [ function_description [ line_number ] ]
           This command fetches and edits the definition of the named function, in the form of a CREATE OR REPLACE FUNCTION
           command. Editing is done in the same way as for \edit. After the editor exits, the updated command waits in the query
           buffer; type semicolon or \g to send it, or \r to cancel.

           The target function can be specified by name alone, or by name and arguments, for example foo(integer, text). The
           argument types must be given if there is more than one function of the same name.

           If no function is specified, a blank CREATE FUNCTION template is presented for editing.

           If a line number is specified, psql will position the cursor on the specified line of the function body. (Note that
           the function body typically does not begin on the first line of the file.)

               Tip
               See under ENVIRONMENT for how to configure and customize your editor.

       \encoding [ encoding ]
           Sets the client character set encoding. Without an argument, this command shows the current encoding.

       \f [ string ]
           Sets the field separator for unaligned query output. The default is the vertical bar (|). See also \pset for a
           generic way of setting output options.

       \g [ filename ]
       \g [ |command ]
           Sends the current query input buffer to the server, and optionally stores the query's output in filename or pipes the
           output to the shell command command. The file or command is written to only if the query successfully returns zero or
           more tuples, not if the query fails or is a non-data-returning SQL command.

           A bare \g is essentially equivalent to a semicolon. A \g with argument is a "one-shot" alternative to the \o command.

       \gset [ prefix ]
           Sends the current query input buffer to the server and stores the query's output into psql variables (see Variables).
           The query to be executed must return exactly one row. Each column of the row is stored into a separate variable,
           named the same as the column. For example:

               => SELECT 'hello' AS var1, 10 AS var2
               -> \gset
               => \echo :var1 :var2
               hello 10

           If you specify a prefix, that string is prepended to the query's column names to create the variable names to use:

               => SELECT 'hello' AS var1, 10 AS var2
               -> \gset result_
               => \echo :result_var1 :result_var2
               hello 10

           If a column result is NULL, the corresponding variable is unset rather than being set.

           If the query fails or does not return one row, no variables are changed.

       \h or \help [ command ]
           Gives syntax help on the specified SQL command. If command is not specified, then psql will list all the commands for
           which syntax help is available. If command is an asterisk (*), then syntax help on all SQL commands is shown.

               Note
               To simplify typing, commands that consists of several words do not have to be quoted. Thus it is fine to type
               \help alter table.

       \H or \html
           Turns on HTML query output format. If the HTML format is already on, it is switched back to the default aligned text
           format. This command is for compatibility and convenience, but see \pset about setting other output options.

       \i or \include filename
           Reads input from the file filename and executes it as though it had been typed on the keyboard.

               Note
               If you want to see the lines on the screen as they are read you must set the variable ECHO to all.

       \ir or \include_relative filename
           The \ir command is similar to \i, but resolves relative file names differently. When executing in interactive mode,
           the two commands behave identically. However, when invoked from a script, \ir interprets file names relative to the
           directory in which the script is located, rather than the current working directory.

       \l[+] or \list[+] [ pattern ]
           List the databases in the server and show their names, owners, character set encodings, and access privileges. If
           pattern is specified, only databases whose names match the pattern are listed. If + is appended to the command name,
           database sizes, default tablespaces, and descriptions are also displayed. (Size information is only available for
           databases that the current user can connect to.)

       \lo_export loid filename
           Reads the large object with OID loid from the database and writes it to filename. Note that this is subtly different
           from the server function lo_export, which acts with the permissions of the user that the database server runs as and
           on the server's file system.

               Tip
               Use \lo_list to find out the large object's OID.

       \lo_import filename [ comment ]
           Stores the file into a PostgreSQL large object. Optionally, it associates the given comment with the object. Example:

               foo=> \lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'
               lo_import 152801

           The response indicates that the large object received object ID 152801, which can be used to access the newly-created
           large object in the future. For the sake of readability, it is recommended to always associate a human-readable
           comment with every object. Both OIDs and comments can be viewed with the \lo_list command.

           Note that this command is subtly different from the server-side lo_import because it acts as the local user on the
           local file system, rather than the server's user and file system.

       \lo_list
           Shows a list of all PostgreSQL large objects currently stored in the database, along with any comments provided for
           them.

       \lo_unlink loid
           Deletes the large object with OID loid from the database.

               Tip
               Use \lo_list to find out the large object's OID.

       \o or \out [ filename ]
       \o or \out [ |command ]
           Arranges to save future query results to the file filename or pipe future results to the shell command command. If no
           argument is specified, the query output is reset to the standard output.

           "Query results" includes all tables, command responses, and notices obtained from the database server, as well as
           output of various backslash commands that query the database (such as \d), but not error messages.

               Tip
               To intersperse text output in between query results, use \qecho.

       \p or \print
           Print the current query buffer to the standard output.

       \password [ username ]
           Changes the password of the specified user (by default, the current user). This command prompts for the new password,
           encrypts it, and sends it to the server as an ALTER ROLE command. This makes sure that the new password does not
           appear in cleartext in the command history, the server log, or elsewhere.

       \prompt [ text ] name
           Prompts the user to supply text, which is assigned to the variable name. An optional prompt string, text, can be
           specified. (For multiword prompts, surround the text with single quotes.)

           By default, \prompt uses the terminal for input and output. However, if the -f command line switch was used, \prompt
           uses standard input and standard output.

       \pset [ option [ value ] ]
           This command sets options affecting the output of query result tables.  option indicates which option is to be set.
           The semantics of value vary depending on the selected option. For some options, omitting value causes the option to
           be toggled or unset, as described under the particular option. If no such behavior is mentioned, then omitting value
           just results in the current setting being displayed.


           \pset without any arguments displays the current status of all printing options.

           Adjustable printing options are:

           border
               The value must be a number. In general, the higher the number the more borders and lines the tables will have,
               but this depends on the particular format. In HTML format, this will translate directly into the border=...
               attribute; in the other formats only values 0 (no border), 1 (internal dividing lines), and 2 (table frame) make
               sense.  latex and latex-longtable also support a border value of 3 which adds a dividing line between each row.

           columns
               Sets the target width for the wrapped format, and also the width limit for determining whether output is wide
               enough to require the pager or switch to the vertical display in expanded auto mode. Zero (the default) causes
               the target width to be controlled by the environment variable COLUMNS, or the detected screen width if COLUMNS is
               not set. In addition, if columns is zero then the wrapped format only affects screen output. If columns is
               nonzero then file and pipe output is wrapped to that width as well.

           expanded (or x)
               If value is specified it must be either on or off, which will enable or disable expanded mode, or auto. If value
               is omitted the command toggles between the on and off settings. When expanded mode is enabled, query results are
               displayed in two columns, with the column name on the left and the data on the right. This mode is useful if the
               data wouldn't fit on the screen in the normal "horizontal" mode. In the auto setting, the expanded mode is used
               whenever the query output is wider than the screen, otherwise the regular mode is used. The auto setting is only
               effective in the aligned and wrapped formats. In other formats, it always behaves as if the expanded mode is off.

           fieldsep
               Specifies the field separator to be used in unaligned output format. That way one can create, for example, tab-
               or comma-separated output, which other programs might prefer. To set a tab as field separator, type \pset
               fieldsep '\t'. The default field separator is '|' (a vertical bar).

           fieldsep_zero
               Sets the field separator to use in unaligned output format to a zero byte.

           footer
               If value is specified it must be either on or off which will enable or disable display of the table footer (the
               (n rows) count). If value is omitted the command toggles footer display on or off.

           format
               Sets the output format to one of unaligned, aligned, wrapped, html, latex (uses tabular), latex-longtable, or
               troff-ms. Unique abbreviations are allowed. (That would mean one letter is enough.)

               unaligned format writes all columns of a row on one line, separated by the currently active field separator. This
               is useful for creating output that might be intended to be read in by other programs (for example, tab-separated
               or comma-separated format).

               aligned format is the standard, human-readable, nicely formatted text output; this is the default.

               wrapped format is like aligned but wraps wide data values across lines to make the output fit in the target
               column width. The target width is determined as described under the columns option. Note that psql will not
               attempt to wrap column header titles; therefore, wrapped format behaves the same as aligned if the total width
               needed for column headers exceeds the target.

               The html, latex, latex-longtable, and troff-ms formats put out tables that are intended to be included in
               documents using the respective mark-up language. They are not complete documents! This might not be necessary in
               HTML, but in LaTeX you must have a complete document wrapper.  latex-longtable also requires the LaTeX longtable
               and booktabs packages.

           linestyle
               Sets the border line drawing style to one of ascii, old-ascii or unicode. Unique abbreviations are allowed. (That
               would mean one letter is enough.) The default setting is ascii. This option only affects the aligned and wrapped
               output formats.

               ascii style uses plain ASCII characters. Newlines in data are shown using a + symbol in the right-hand margin.
               When the wrapped format wraps data from one line to the next without a newline character, a dot (.) is shown in
               the right-hand margin of the first line, and again in the left-hand margin of the following line.

               old-ascii style uses plain ASCII characters, using the formatting style used in PostgreSQL 8.4 and earlier.
               Newlines in data are shown using a : symbol in place of the left-hand column separator. When the data is wrapped
               from one line to the next without a newline character, a ; symbol is used in place of the left-hand column
               separator.

               unicode style uses Unicode box-drawing characters. Newlines in data are shown using a carriage return symbol in
               the right-hand margin. When the data is wrapped from one line to the next without a newline character, an
               ellipsis symbol is shown in the right-hand margin of the first line, and again in the left-hand margin of the
               following line.

               When the border setting is greater than zero, this option also determines the characters with which the border
               lines are drawn. Plain ASCII characters work everywhere, but Unicode characters look nicer on displays that
               recognize them.

           null
               Sets the string to be printed in place of a null value. The default is to print nothing, which can easily be
               mistaken for an empty string. For example, one might prefer \pset null '(null)'.

           numericlocale
               If value is specified it must be either on or off which will enable or disable display of a locale-specific
               character to separate groups of digits to the left of the decimal marker. If value is omitted the command toggles
               between regular and locale-specific numeric output.

           pager
               Controls use of a pager program for query and psql help output. If the environment variable PAGER is set, the
               output is piped to the specified program. Otherwise a platform-dependent default (such as more) is used.

               When the pager option is off, the pager program is not used. When the pager option is on, the pager is used when
               appropriate, i.e., when the output is to a terminal and will not fit on the screen. The pager option can also be
               set to always, which causes the pager to be used for all terminal output regardless of whether it fits on the
               screen.  \pset pager without a value toggles pager use on and off.

           recordsep
               Specifies the record (line) separator to use in unaligned output format. The default is a newline character.

           recordsep_zero
               Sets the record separator to use in unaligned output format to a zero byte.

           tableattr (or T)
               In HTML format, this specifies attributes to be placed inside the table tag. This could for example be
               cellpadding or bgcolor. Note that you probably don't want to specify border here, as that is already taken care
               of by \pset border. If no value is given, the table attributes are unset.

               In latex-longtable format, this controls the proportional width of each column containing a left-aligned data
               type. It is specified as a whitespace-separated list of values, e.g.  '0.2 0.2 0.6'. Unspecified output columns
               use the last specified value.

           title
               Sets the table title for any subsequently printed tables. This can be used to give your output descriptive tags.
               If no value is given, the title is unset.

           tuples_only (or t)
               If value is specified it must be either on or off which will enable or disable tuples-only mode. If value is
               omitted the command toggles between regular and tuples-only output. Regular output includes extra information
               such as column headers, titles, and various footers. In tuples-only mode, only actual table data is shown.

           Illustrations of how these different formats look can be seen in the EXAMPLES section.

               Tip
               There are various shortcut commands for \pset. See \a, \C, \H, \t, \T, and \x.

       \q or \quit
           Quits the psql program. In a script file, only execution of that script is terminated.

       \qecho text [ ... ]
           This command is identical to \echo except that the output will be written to the query output channel, as set by \o.

       \r or \reset
           Resets (clears) the query buffer.

       \s [ filename ]
           Print psql's command line history to filename. If filename is omitted, the history is written to the standard output
           (using the pager if appropriate). This command is not available if psql was built without Readline support.

       \set [ name [ value [ ... ] ] ]
           Sets the psql variable name to value, or if more than one value is given, to the concatenation of all of them. If
           only one argument is given, the variable is set with an empty value. To unset a variable, use the \unset command.

           \set without any arguments displays the names and values of all currently-set psql variables.

           Valid variable names can contain letters, digits, and underscores. See the section Variables below for details.
           Variable names are case-sensitive.

           Although you are welcome to set any variable to anything you want, psql treats several variables as special. They are
           documented in the section about variables.

               Note
               This command is unrelated to the SQL command SET(7).

       \setenv name [ value ]
           Sets the environment variable name to value, or if the value is not supplied, unsets the environment variable.
           Example:

               testdb=> \setenv PAGER less
               testdb=> \setenv LESS -imx4F

       \sf[+] function_description
           This command fetches and shows the definition of the named function, in the form of a CREATE OR REPLACE FUNCTION
           command. The definition is printed to the current query output channel, as set by \o.

           The target function can be specified by name alone, or by name and arguments, for example foo(integer, text). The
           argument types must be given if there is more than one function of the same name.

           If + is appended to the command name, then the output lines are numbered, with the first line of the function body
           being line 1.

       \t
           Toggles the display of output column name headings and row count footer. This command is equivalent to \pset
           tuples_only and is provided for convenience.

       \T table_options
           Specifies attributes to be placed within the table tag in HTML output format. This command is equivalent to \pset
           tableattr table_options.

       \timing [ on | off ]
           Without parameter, toggles a display of how long each SQL statement takes, in milliseconds. With parameter, sets
           same.

       \unset name
           Unsets (deletes) the psql variable name.

       \w or \write filename
       \w or \write |command
           Outputs the current query buffer to the file filename or pipes it to the shell command command.

       \watch [ seconds ]
           Repeatedly execute the current query buffer (like \g) until interrupted or the query fails. Wait the specified number
           of seconds (default 2) between executions.

       \x [ on | off | auto ]
           Sets or toggles expanded table formatting mode. As such it is equivalent to \pset expanded.

       \z [ pattern ]
           Lists tables, views and sequences with their associated access privileges. If a pattern is specified, only tables,
           views and sequences whose names match the pattern are listed.

           This is an alias for \dp ("display privileges").

       \! [ command ]
           Escapes to a separate shell or executes the shell command command. The arguments are not further interpreted; the
           shell will see them as-is. In particular, the variable substitution rules and backslash escapes do not apply.

       \?
           Shows help information about the backslash commands.

       Patterns
           The various \d commands accept a pattern parameter to specify the object name(s) to be displayed. In the simplest
           case, a pattern is just the exact name of the object. The characters within a pattern are normally folded to lower
           case, just as in SQL names; for example, \dt FOO will display the table named foo. As in SQL names, placing double
           quotes around a pattern stops folding to lower case. Should you need to include an actual double quote character in a
           pattern, write it as a pair of double quotes within a double-quote sequence; again this is in accord with the rules
           for SQL quoted identifiers. For example, \dt "FOO""BAR" will display the table named FOO"BAR (not foo"bar). Unlike
           the normal rules for SQL names, you can put double quotes around just part of a pattern, for instance \dt FOO"FOO"BAR
           will display the table named fooFOObar.

           Whenever the pattern parameter is omitted completely, the \d commands display all objects that are visible in the
           current schema search path -- this is equivalent to using * as the pattern. (An object is said to be visible if its
           containing schema is in the search path and no object of the same kind and name appears earlier in the search path.
           This is equivalent to the statement that the object can be referenced by name without explicit schema qualification.)
           To see all objects in the database regardless of visibility, use *.*  as the pattern.

           Within a pattern, * matches any sequence of characters (including no characters) and ?  matches any single character.
           (This notation is comparable to Unix shell file name patterns.) For example, \dt int* displays tables whose names
           begin with int. But within double quotes, * and ?  lose these special meanings and are just matched literally.

           A pattern that contains a dot (.) is interpreted as a schema name pattern followed by an object name pattern. For
           example, \dt foo*.*bar* displays all tables whose table name includes bar that are in schemas whose schema name
           starts with foo. When no dot appears, then the pattern matches only objects that are visible in the current schema
           search path. Again, a dot within double quotes loses its special meaning and is matched literally.

           Advanced users can use regular-expression notations such as character classes, for example [0-9] to match any digit.
           All regular expression special characters work as specified in Section 9.7.3, "POSIX Regular Expressions", in the
           documentation, except for .  which is taken as a separator as mentioned above, * which is translated to the
           regular-expression notation .*, ?  which is translated to ., and $ which is matched literally. You can emulate these
           pattern characters at need by writing ?  for ., (R+|) for R*, or (R|) for R?.  $ is not needed as a
           regular-expression character since the pattern must match the whole name, unlike the usual interpretation of regular
           expressions (in other words, $ is automatically appended to your pattern). Write * at the beginning and/or end if you
           don't wish the pattern to be anchored. Note that within double quotes, all regular expression special characters lose
           their special meanings and are matched literally. Also, the regular expression special characters are matched
           literally in operator name patterns (i.e., the argument of \do).

   Advanced Features
       Variables
           psql provides variable substitution features similar to common Unix command shells. Variables are simply name/value
           pairs, where the value can be any string of any length. The name must consist of letters (including non-Latin
           letters), digits, and underscores.

           To set a variable, use the psql meta-command \set. For example,

               testdb=> \set foo bar

           sets the variable foo to the value bar. To retrieve the content of the variable, precede the name with a colon, for
           example:

               testdb=> \echo :foo
               bar

           This works in both regular SQL commands and meta-commands; there is more detail in SQL Interpolation, below.

           If you call \set without a second argument, the variable is set, with an empty string as value. To unset (i.e.,
           delete) a variable, use the command \unset. To show the values of all variables, call \set without any argument.

               Note
               The arguments of \set are subject to the same substitution rules as with other commands. Thus you can construct
               interesting references such as \set :foo 'something' and get "soft links" or "variable variables" of Perl or PHP
               fame, respectively. Unfortunately (or fortunately?), there is no way to do anything useful with these constructs.
               On the other hand, \set bar :foo is a perfectly valid way to copy a variable.

           A number of these variables are treated specially by psql. They represent certain option settings that can be changed
           at run time by altering the value of the variable, or in some cases represent changeable state of psql. Although you
           can use these variables for other purposes, this is not recommended, as the program behavior might grow really
           strange really quickly. By convention, all specially treated variables' names consist of all upper-case ASCII letters
           (and possibly digits and underscores). To ensure maximum compatibility in the future, avoid using such variable names
           for your own purposes. A list of all specially treated variables follows.

           AUTOCOMMIT
               When on (the default), each SQL command is automatically committed upon successful completion. To postpone commit
               in this mode, you must enter a BEGIN or START TRANSACTION SQL command. When off or unset, SQL commands are not
               committed until you explicitly issue COMMIT or END. The autocommit-off mode works by issuing an implicit BEGIN
               for you, just before any command that is not already in a transaction block and is not itself a BEGIN or other
               transaction-control command, nor a command that cannot be executed inside a transaction block (such as VACUUM).

                   Note
                   In autocommit-off mode, you must explicitly abandon any failed transaction by entering ABORT or ROLLBACK.
                   Also keep in mind that if you exit the session without committing, your work will be lost.

                   Note
                   The autocommit-on mode is PostgreSQL's traditional behavior, but autocommit-off is closer to the SQL spec. If
                   you prefer autocommit-off, you might wish to set it in the system-wide psqlrc file or your ~/.psqlrc file.

           COMP_KEYWORD_CASE
               Determines which letter case to use when completing an SQL key word. If set to lower or upper, the completed word
               will be in lower or upper case, respectively. If set to preserve-lower or preserve-upper (the default), the
               completed word will be in the case of the word already entered, but words being completed without anything
               entered will be in lower or upper case, respectively.

           DBNAME
               The name of the database you are currently connected to. This is set every time you connect to a database
               (including program start-up), but can be unset.

           ECHO
               If set to all, all nonempty input lines are printed to standard output as they are read. (This does not apply to
               lines read interactively.) To select this behavior on program start-up, use the switch -a. If set to queries,
               psql prints each query to standard output as it is sent to the server. The switch for this is -e.

           ECHO_HIDDEN
               When this variable is set to on and a backslash command queries the database, the query is first shown. This
               feature helps you to study PostgreSQL internals and provide similar functionality in your own programs. (To
               select this behavior on program start-up, use the switch -E.) If you set the variable to the value noexec, the
               queries are just shown but are not actually sent to the server and executed.

           ENCODING
               The current client character set encoding.

           FETCH_COUNT
               If this variable is set to an integer value > 0, the results of SELECT queries are fetched and displayed in
               groups of that many rows, rather than the default behavior of collecting the entire result set before display.
               Therefore only a limited amount of memory is used, regardless of the size of the result set. Settings of 100 to
               1000 are commonly used when enabling this feature. Keep in mind that when using this feature, a query might fail
               after having already displayed some rows.

                   Tip
                   Although you can use any output format with this feature, the default aligned format tends to look bad
                   because each group of FETCH_COUNT rows will be formatted separately, leading to varying column widths across
                   the row groups. The other output formats work better.

           HISTCONTROL
               If this variable is set to ignorespace, lines which begin with a space are not entered into the history list. If
               set to a value of ignoredups, lines matching the previous history line are not entered. A value of ignoreboth
               combines the two options. If unset, or if set to any other value than those above, all lines read in interactive
               mode are saved on the history list.

                   Note
                   This feature was shamelessly plagiarized from Bash.

           HISTFILE
               The file name that will be used to store the history list. The default value is ~/.psql_history. For example,
               putting:

                   \set HISTFILE ~/.psql_history- :DBNAME

               in ~/.psqlrc will cause psql to maintain a separate history for each database.

                   Note
                   This feature was shamelessly plagiarized from Bash.

           HISTSIZE
               The number of commands to store in the command history. The default value is 500.

                   Note
                   This feature was shamelessly plagiarized from Bash.

           HOST
               The database server host you are currently connected to. This is set every time you connect to a database
               (including program start-up), but can be unset.

           IGNOREEOF
               If unset, sending an EOF character (usually Control+D) to an interactive session of psql will terminate the
               application. If set to a numeric value, that many EOF characters are ignored before the application terminates.
               If the variable is set but has no numeric value, the default is 10.

                   Note
                   This feature was shamelessly plagiarized from Bash.

           LASTOID
               The value of the last affected OID, as returned from an INSERT or \lo_import command. This variable is only
               guaranteed to be valid until after the result of the next SQL command has been displayed.

           ON_ERROR_ROLLBACK
               When set to on, if a statement in a transaction block generates an error, the error is ignored and the
               transaction continues. When set to interactive, such errors are only ignored in interactive sessions, and not
               when reading script files. When unset or set to off, a statement in a transaction block that generates an error
               aborts the entire transaction. The error rollback mode works by issuing an implicit SAVEPOINT for you, just
               before each command that is in a transaction block, and then rolling back to the savepoint if the command fails.

           ON_ERROR_STOP
               By default, command processing continues after an error. When this variable is set to on, processing will instead
               stop immediately. In interactive mode, psql will return to the command prompt; otherwise, psql will exit,
               returning error code 3 to distinguish this case from fatal error conditions, which are reported using error code
               1. In either case, any currently running scripts (the top-level script, if any, and any other scripts which it
               may have in invoked) will be terminated immediately. If the top-level command string contained multiple SQL
               commands, processing will stop with the current command.

           PORT
               The database server port to which you are currently connected. This is set every time you connect to a database
               (including program start-up), but can be unset.

           PROMPT1
           PROMPT2
           PROMPT3
               These specify what the prompts psql issues should look like. See Prompting below.

           QUIET
               Setting this variable to on is equivalent to the command line option -q. It is probably not too useful in
               interactive mode.

           SINGLELINE
               Setting this variable to on is equivalent to the command line option -S.

           SINGLESTEP
               Setting this variable to on is equivalent to the command line option -s.

           USER
               The database user you are currently connected as. This is set every time you connect to a database (including
               program start-up), but can be unset.

           VERBOSITY
               This variable can be set to the values default, verbose, or terse to control the verbosity of error reports.

       SQL Interpolation
           A key feature of psql variables is that you can substitute ("interpolate") them into regular SQL statements, as well
           as the arguments of meta-commands. Furthermore, psql provides facilities for ensuring that variable values used as
           SQL literals and identifiers are properly quoted. The syntax for interpolating a value without any quoting is to
           prepend the variable name with a colon (:). For example,

               testdb=> \set foo 'my_table'
               testdb=> SELECT * FROM :foo;

           would query the table my_table. Note that this may be unsafe: the value of the variable is copied literally, so it
           can contain unbalanced quotes, or even backslash commands. You must make sure that it makes sense where you put it.

           When a value is to be used as an SQL literal or identifier, it is safest to arrange for it to be quoted. To quote the
           value of a variable as an SQL literal, write a colon followed by the variable name in single quotes. To quote the
           value as an SQL identifier, write a colon followed by the variable name in double quotes. These constructs deal
           correctly with quotes and other special characters embedded within the variable value. The previous example would be
           more safely written this way:

               testdb=> \set foo 'my_table'
               testdb=> SELECT * FROM :"foo";

           Variable interpolation will not be performed within quoted SQL literals and identifiers. Therefore, a construction
           such as ':foo' doesn't work to produce a quoted literal from a variable's value (and it would be unsafe if it did
           work, since it wouldn't correctly handle quotes embedded in the value).

           One example use of this mechanism is to copy the contents of a file into a table column. First load the file into a
           variable and then interpolate the variable's value as a quoted string:

               testdb=> \set content `cat my_file.txt`
               testdb=> INSERT INTO my_table VALUES (:'content');

           (Note that this still won't work if my_file.txt contains NUL bytes.  psql does not support embedded NUL bytes in
           variable values.)

           Since colons can legally appear in SQL commands, an apparent attempt at interpolation (that is, :name, :'name', or
           :"name") is not replaced unless the named variable is currently set. In any case, you can escape a colon with a
           backslash to protect it from substitution.

           The colon syntax for variables is standard SQL for embedded query languages, such as ECPG. The colon syntaxes for
           array slices and type casts are PostgreSQL extensions, which can sometimes conflict with the standard usage. The
           colon-quote syntax for escaping a variable's value as an SQL literal or identifier is a psql extension.

       Prompting
           The prompts psql issues can be customized to your preference. The three variables PROMPT1, PROMPT2, and PROMPT3
           contain strings and special escape sequences that describe the appearance of the prompt. Prompt 1 is the normal
           prompt that is issued when psql requests a new command. Prompt 2 is issued when more input is expected during command
           input because the command was not terminated with a semicolon or a quote was not closed. Prompt 3 is issued when you
           run an SQL COPY command and you are expected to type in the row values on the terminal.

           The value of the selected prompt variable is printed literally, except where a percent sign (%) is encountered.
           Depending on the next character, certain other text is substituted instead. Defined substitutions are:

           %M
               The full host name (with domain name) of the database server, or [local] if the connection is over a Unix domain
               socket, or [local:/dir/name], if the Unix domain socket is not at the compiled in default location.

           %m
               The host name of the database server, truncated at the first dot, or [local] if the connection is over a Unix
               domain socket.

           %>
               The port number at which the database server is listening.

           %n
               The database session user name. (The expansion of this value might change during a database session as the result
               of the command SET SESSION AUTHORIZATION.)

           %/
               The name of the current database.

           %~
               Like %/, but the output is ~ (tilde) if the database is your default database.

           %#
               If the session user is a database superuser, then a #, otherwise a >. (The expansion of this value might change
               during a database session as the result of the command SET SESSION AUTHORIZATION.)

           %R
               In prompt 1 normally =, but ^ if in single-line mode, and !  if the session is disconnected from the database
               (which can happen if \connect fails). In prompt 2 the sequence is replaced by -, *, a single quote, a double
               quote, or a dollar sign, depending on whether psql expects more input because the command wasn't terminated yet,
               because you are inside a /* ... */ comment, or because you are inside a quoted or dollar-escaped string. In
               prompt 3 the sequence doesn't produce anything.

           %x
               Transaction status: an empty string when not in a transaction block, or * when in a transaction block, or !  when
               in a failed transaction block, or ?  when the transaction state is indeterminate (for example, because there is
               no connection).

           %digits
               The character with the indicated octal code is substituted.

           %:name:
               The value of the psql variable name. See the section Variables for details.

           %`command`
               The output of command, similar to ordinary "back-tick" substitution.

           %[ ... %]
               Prompts can contain terminal control characters which, for example, change the color, background, or style of the
               prompt text, or change the title of the terminal window. In order for the line editing features of Readline to
               work properly, these non-printing control characters must be designated as invisible by surrounding them with %[
               and %]. Multiple pairs of these can occur within the prompt. For example:

                   testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%]%# '

               results in a boldfaced (1;) yellow-on-black (33;40) prompt on VT100-compatible, color-capable terminals.
           To insert a percent sign into your prompt, write %%. The default prompts are '%/%R%# ' for prompts 1 and 2, and '>> '
           for prompt 3.

               Note
               This feature was shamelessly plagiarized from tcsh.

       Command-Line Editing
           psql supports the Readline library for convenient line editing and retrieval. The command history is automatically
           saved when psql exits and is reloaded when psql starts up. Tab-completion is also supported, although the completion
           logic makes no claim to be an SQL parser. The queries generated by tab-completion can also interfere with other SQL
           commands, e.g.  SET TRANSACTION ISOLATION LEVEL. If for some reason you do not like the tab completion, you can turn
           it off by putting this in a file named .inputrc in your home directory:

               $if psql
               set disable-completion on
               $endif

           (This is not a psql but a Readline feature. Read its documentation for further details.)

ENVIRONMENT
       COLUMNS
           If \pset columns is zero, controls the width for the wrapped format and width for determining if wide output requires
           the pager or should be switched to the vertical format in expanded auto mode.

       PAGER
           If the query results do not fit on the screen, they are piped through this command. Typical values are more or less.
           The default is platform-dependent. The use of the pager can be disabled by using the \pset command.

       PGDATABASE
       PGHOST
       PGPORT
       PGUSER
           Default connection parameters (see Section 31.14, "Environment Variables", in the documentation).

       PSQL_EDITOR
       EDITOR
       VISUAL
           Editor used by the \e and \ef commands. The variables are examined in the order listed; the first that is set is
           used.

           The built-in default editors are vi on Unix systems and notepad.exe on Windows systems.

       PSQL_EDITOR_LINENUMBER_ARG
           When \e or \ef is used with a line number argument, this variable specifies the command-line argument used to pass
           the starting line number to the user's editor. For editors such as Emacs or vi, this is a plus sign. Include a
           trailing space in the value of the variable if there needs to be space between the option name and the line number.
           Examples:

               PSQL_EDITOR_LINENUMBER_ARG='+'
               PSQL_EDITOR_LINENUMBER_ARG='--line '

           The default is + on Unix systems (corresponding to the default editor vi, and useful for many other common editors);
           but there is no default on Windows systems.

       PSQL_HISTORY
           Alternative location for the command history file. Tilde (~) expansion is performed.

       PSQLRC
           Alternative location of the user's .psqlrc file. Tilde (~) expansion is performed.

       SHELL
           Command executed by the \!  command.

       TMPDIR
           Directory for storing temporary files. The default is /tmp.

       This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section
       31.14, "Environment Variables", in the documentation).

FILES
       psqlrc and ~/.psqlrc
           Unless it is passed an -X or -c option, psql attempts to read and execute commands from the system-wide startup file
           (psqlrc) and then the user's personal startup file (~/.psqlrc), after connecting to the database but before accepting
           normal commands. These files can be used to set up the client and/or the server to taste, typically with \set and SET
           commands.

           The system-wide startup file is named psqlrc and is sought in the installation's "system configuration" directory,
           which is most reliably identified by running pg_config --sysconfdir. By default this directory will be ../etc/
           relative to the directory containing the PostgreSQL executables. The name of this directory can be set explicitly via
           the PGSYSCONFDIR environment variable.

           The user's personal startup file is named .psqlrc and is sought in the invoking user's home directory. On Windows,
           which lacks such a concept, the personal startup file is named %APPDATA%\postgresql\psqlrc.conf. The location of the
           user's startup file can be set explicitly via the PSQLRC environment variable.

           Both the system-wide startup file and the user's personal startup file can be made psql-version-specific by appending
           a dash and the PostgreSQL major or minor release number to the file name, for example ~/.psqlrc-9.2 or
           ~/.psqlrc-9.2.5. The most specific version-matching file will be read in preference to a non-version-specific file.

       .psql_history
           The command-line history is stored in the file ~/.psql_history, or %APPDATA%\postgresql\psql_history on Windows.

           The location of the history file can be set explicitly via the PSQL_HISTORY environment variable.

NOTES
          In an earlier life psql allowed the first argument of a single-letter backslash command to start directly after the
           command, without intervening whitespace. As of PostgreSQL 8.4 this is no longer allowed.

          psql works best with servers of the same or an older major version. Backslash commands are particularly likely to
           fail if the server is of a newer version than psql itself. However, backslash commands of the \d family should work
           with servers of versions back to 7.4, though not necessarily with servers newer than psql itself. The general
           functionality of running SQL commands and displaying query results should also work with servers of a newer major
           version, but this cannot be guaranteed in all cases.

           If you want to use psql to connect to several servers of different major versions, it is recommended that you use the
           newest version of psql. Alternatively, you can keep a copy of psql from each major version around and be sure to use
           the version that matches the respective server. But in practice, this additional complication should not be
           necessary.

NOTES FOR WINDOWS USERS
       psql is built as a "console application". Since the Windows console windows use a different encoding than the rest of the
       system, you must take special care when using 8-bit characters within psql. If psql detects a problematic console code
       page, it will warn you at startup. To change the console code page, two things are necessary:

          Set the code page by entering cmd.exe /c chcp 1252. (1252 is a code page that is appropriate for German; replace it
           with your value.) If you are using Cygwin, you can put this command in /etc/profile.

          Set the console font to Lucida Console, because the raster font does not work with the ANSI code page.

EXAMPLES
       The first example shows how to spread a command over several lines of input. Notice the changing prompt:

           testdb=> CREATE TABLE my_table (
           testdb(>  first integer not null default 0,
           testdb(>  second text)
           testdb-> ;
           CREATE TABLE

       Now look at the table definition again:

           testdb=> \d my_table
                        Table "my_table"
            Attribute |  Type   |      Modifier
           -----------+---------+--------------------
            first     | integer | not null default 0
            second    | text    |

       Now we change the prompt to something more interesting:

           testdb=> \set PROMPT1 '%n@%m %~%R%# '
           peter@localhost testdb=>

       Let's assume you have filled the table with data and want to take a look at it:

           peter@localhost testdb=> SELECT * FROM my_table;
            first | second
           -------+--------
                1 | one
                2 | two
                3 | three
                4 | four
           (4 rows)

       You can display tables in different ways by using the \pset command:

           peter@localhost testdb=> \pset border 2
           Border style is 2.
           peter@localhost testdb=> SELECT * FROM my_table;
           +-------+--------+
           | first | second |
           +-------+--------+
           |     1 | one    |
           |     2 | two    |
           |     3 | three  |
           |     4 | four   |
           +-------+--------+
           (4 rows)

           peter@localhost testdb=> \pset border 0
           Border style is 0.
           peter@localhost testdb=> SELECT * FROM my_table;
           first second
           ----- ------
               1 one
               2 two
               3 three
               4 four
           (4 rows)

           peter@localhost testdb=> \pset border 1
           Border style is 1.
           peter@localhost testdb=> \pset format unaligned
           Output format is unaligned.
           peter@localhost testdb=> \pset fieldsep ","
           Field separator is ",".
           peter@localhost testdb=> \pset tuples_only
           Showing only tuples.
           peter@localhost testdb=> SELECT second, first FROM my_table;
           one,1
           two,2
           three,3
           four,4

       Alternatively, use the short commands:

           peter@localhost testdb=> \a \t \x
           Output format is aligned.
           Tuples only is off.
           Expanded display is on.
           peter@localhost testdb=> SELECT * FROM my_table;
           -[ RECORD 1 ]-
           first  | 1
           second | one
           -[ RECORD 2 ]-
           first  | 2
           second | two
           -[ RECORD 3 ]-
           first  | 3
           second | three
           -[ RECORD 4 ]-
           first  | 4
           second | four




PostgreSQL 9.4.3                                              2015                                                       PSQL(1)


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