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mclient man-page


mclient −
the MonetDB command-line tool


[ options ] [ file or database [ file
... ] ]

mclient −−help


MonetDB is a
database management system that is developed from a
main-memory perspective with use of a fully decomposed
storage model, automatic index management, extensibility of
data types and search accelerators, and a SQL frontend.

is the command-line interface to the MonetDB server.

If the
−−statement=query (−s
query) option is given, the query is executed. If any
files are listed after the options, queries are read from
the files and executed. The special filename
refers to standard input. Note that if there is both a
−−statement option and filename
arguments, the query given with
−−statement is executed first. If no
−−statement option is given and no files
are specified on the command line, mclient reads
queries from standard input.

When reading
from standard input, if standard input is a terminal or if
the −−interactive (−i)
option is given, mclient interprets lines starting
with \ (backslash) specially. See the section

mclient starts parsing command line options, it reads
a .monetdb file. If the environment variable
DOTMONETDBFILE is set, it reads the file pointed to
by that variable instead. When unset, mclient
searches for a .monetdb file in the current working
directory, and if that doesn’t exist, in the current
user’s home directory. This file can contain defaults
for the flags user, password, language,
save_history, format, and width. For
example, an entry in a .monetdb file that sets the
default language for mclient to mal looks like this:
language=mal. To disable reading the .monetdb
file, set the variable DOTMONETDBFILE to the empty
string in the environment.




Print usage information and


Print version information and

(−E encoding)

Specify the character encoding
of the input. The option applies to both the standard input
of mclient and to the argument of the
−−statement (−s) option but
not to the contents of files specified on the command line
(except for which refers to standard input)
or files specified using the \< command (those
must be encoded using UTF-8). The default encoding is taken
from the locale.

(−l language)

Specify the query language. The
following languages are recognized: mal and
sql. A unique prefix suffices. When the
−−language option is omitted, the default
of sql is assumed.

(−d database)

Specify the name or URI of the
database to connect to. The -d can be omitted if an
equally named file does not exist in the current directory.
As such, the first non-option argument will be interpreted
as database to connect to if the argument does not exist as
file. Valid URIs are as returned by ‘monetdb
discover‘, see monetdb(1), and look like

(−h hostname)

Specify the name of the host on
which the server runs (default: localhost). When the
argument starts with a forward slash (/), host is assumed to
be the directory where the UNIX sockets are stored for
platforms where these are supported.

(−p portnr)

Specify the portnumber of the
server (default: 50000).


When reading from standard
input, interpret lines starting with \ (backslash)
specially. See the section BACKSLASH COMMANDS below. This is
the default if standard input is a terminal. The optional
timermode argument controls the format of the time
reported for queries. Note that no space is allowed between
−i and timermode. The default mode is
human which adjusts the time precision to the
measured value. The modes ms, s and m
force millisecond, second and minute + second precision

(−u user)

Specify the user to connect as.
If this flag is absent, the client will ask for a user name,
unless a default was found in .monetdb file.

(−f format)

Specify the output format. The
possible values are sql, expanded, x,
csv, tab, raw, and xml.
csv is comma-separated values, tab is
tab-separated values, raw is no special formatting
(data is dumped the way the server sends it to the client),
sql is a pretty format which is meant for human
consumption where columns are clearly shown, expanded
and x are synonyms and are another pretty format
meant for human consumption where column values are printed
in full and below each other, and xml is a valid (in
the XML sense) document. In addition to plain csv,
two other forms are possible. csv=c uses
c as column separator; csv+c uses
c as column separator and produces a single header
line in addition to the data.


Echo the query. Note that using
this option slows down processing.


Load and save the command line
history (default off).

(−L logfile)

Save client/server interaction
in the specified file.

(−s stmt)

Execute the specified query.
The query is run before any queries from files specified on
the command line are run.


Do not tell the client’s
timezone to the server.


Trace network interaction
between mclient and the server.

(−| cmd)

Send query output through the
specified cmd. One cmd is started for each
query. Note that the | will have to be quoted or else
the shell will interpret it.

SQL Options

nullstr (−n

Set the string to be used as
NULL representation when using the sql, csv, or tab output
formats. If not used, NULL values are represented by the
string "null" in the sql output format, and as the
empty string in the csv and tab output formats. Note that an
argument is required, so in order to use the empty string,
use −n "" (with the space) or


Switch autocommit mode off. By
default, autocommit mode is on.

(−r nr)

If specified, query results
will be paged by an internal pager at the specified number
of lines.

(−w nr)

Specify the width of the
screen. The default is the (initial) width of the


Create an SQL dump.


Use INSERT INTO statements
instead of COPY INTO + CSV values when dumping the data of a
table. This option can be used when trying to load data from
MonetDB into another database, or when e.g. JDBC
applications are used to reload the dump.



cellspacing="0" cellpadding="0">


Show a help message explaining the backslash


Exit mclient.

\< file

Read input from the named

\> file

Write output to the named
file. If no file is specified, write to
standard output.

\| command

Pipe output to the given
command. Each query is piped to a new invocation of
the command. If no command is given, revert to
writing output to standard output.

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Show the readline(3) history.

\L file

Log client/server interaction
in the given file. If no file is specified,
stop logging information.

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Trace what mclient is doing. This is mostly for
debugging purposes.


Echo the query in SQL formatting mode.

\f format

Use the specified format
mode to format the output. Possible modes the same as for
the −−format (−f)

\w width

Set the maximum page width for
rendering in the sql formatting mode. If width
is −1, the page width is unlimited, when
width is 0, use the terminal width. If
width is greater than 0, use the given

\r rows

Use an internal pager using
rows per page. If rows is −1,
stop using the internal pager.


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Dump the complete database. This is equivalent to using
the program msqldump(1).

\D table

Dump the given

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Alias for \dvt.


List database objects of the
given type. Multiple type specifiers can be used at the same
time. The specifiers S, t, v, s,
f and n stand for System, table, view,
sequence, function and schema respectively. Note that
S simply switches on viewing system catalog objects,
which is orthogonal to the other specifiers.


Describe the given
object in the database using SQL statements that
reconstruct the object. The same specifiers as above can be
used, following the same rules. When no specifiers are
given, vt is assumed. The object can be given with or
without a schema, separated by a dot. The object name can
contain the wildcard characters * and _ that
represent zero or more, and exactly one character
respectively. An object name is converted to lowercase,
unless the object name is quoted by double quotes
("). Examples of this, are e.g.
*.mytable, tabletype*, or
"myschema.FOO". Note that wildcard
characters do not work in quoted objects. Quoting follows
SQL quoting rules. Arbitrary parts can be quoted, and two
quotes following each other in a quoted string represent the
quote itself.

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Enable auto commit mode.


Disable auto commit mode.


import data from a CSV (comma-separated values) file into a
table. The file must be readable by the server. $file
is the absolute path name of the file, $table is the
name of the table, $db is the name of the

mclient -d $db
-s "COPY INTO $table FROM ’$file’ USING

import data from a CSV file into a table when the file is to
be read by mclient (e.g. the server has no access to the
file). $file is the (absolute or relative) path name
of the file, $table is the name of the table,
$db is the name of the database.

mclient -d $db
- < $file

Note that in
this latter case, if a count of records is supplied, it
should be at least as large as the number of records
actually present in the CSV file. This, because otherwise
the remainder of the file will be interpreted as SQL

for more information about the COPY INTO query.