The program entry point is the script called pgxn.
pgxn [--help] [--version] COMMAND [--mirror URL] [--verbose] [--yes] ...
The script offers several commands, whose list can be obtained using pgxn --help. The options available for each subcommand can be obtained using pgxn COMMAND --help.
The main commands you may be interested in are install (to download, build and install an extension distribution into the system) and load (to load an installed extension into a database). Commands to perform reverse operations are uninstall and unload. Use download to get a package from a mirror without installing it.
A few options are available to all the commands:
Many commands such as install require a package specification to operate. In its simple form the specification is just the name of a distribution: pgxn install foo means "install the most recent stable release of the foo distribution". If a distribution with given name is not found, many commands will look for an extension with the given name, and will work on it.
The specification allows specifying an operator and a version number, so that pgxn install 'foo<2.0' will install the most recent stable release of the distribution before the release 2.0. The version numbers are ordered according to the Semantic Versioning specification. Supported operators are =, == (alias for =), <, <=, >, >=. Note that you probably need to quote the string as in the example to avoid invoking shell command redirection.
Whenever a command takes a specification in input, it also accepts options --stable, --testing and --unstable to specify the minimum release status accepted. The default is "stable".
A few commands also allow specifying a local archive or local directory containing a distribution: in this case the specification should contain at least a path separator to disambiguate it from a distribution name (for instance pgxn install ./foo.zip) or it should be specified as an URL with file:// schema.
A few commands also allow specifying a remote package with a URL. Currently the schemas http:// and https:// are supported.
Currently the client supports .zip and .tar archives (eventually with gzip and bz2 compression).
Download, build, and install a distribution on the local system.
pgxn install [--help] [--stable | --testing | --unstable] [--pg_config PROG] [--make PROG] [--sudo [PROG] | --nosudo] SPEC
The program takes a package specification identifying the distribution to work with. The download phase is skipped if the distribution specification refers to a local directory or package. The package may be specified with an URL.
Note that the built extension is not loaded in any database: use the command load for this purpose.
The command will run the configure script if available in the package, then will perform make all and make install. It is assumed that the Makefile provided by the distribution uses PGXS to build the extension, but this is not enforced: you may provide any Makefile as long as the expected commands are implemented.
If there are many PostgreSQL installations on the system, the extension will be built and installed against the instance whose pg_config is first found on the PATH. A different instance can be specified using the option --pg_config PATH.
The PGXS build system relies on a presence of GNU Make: in many systems it is installed as gmake or make executable. The program will use the first of them on the path. You can specify an alternative program using --make option.
If the extension is being installed into a system PostgreSQL installation, the install phase will likely require root privileges to be performed. In this case either run the command under sudo or specify the --sudo option: in the latter case sudo will only be invoked during the "install" phase. An optional program PROG to elevate the user privileges can be specified as --sudo option; if none is specified, sudo will be used.
If --sudo is the last option and no PROG is specified, a -- separator may be required to disambiguate the SPEC:
pgxn install --sudo -- foobar
Run a distribution's unit test.
pgxn check [--help] [--stable | --testing | --unstable] [--pg_config PROG] [--make PROG] [-d DBNAME] [-h HOST] [-p PORT] [-U NAME] SPEC
The command takes a package specification identifying the distribution to work with, which can also be a local file or directory or an URL. The distribution is unpacked if required and the installcheck make target is run.
The command doesn't run make all before installcheck: if any file required for testing is to be built, it should be listed as installcheck prerequisite in the Makefile, for instance:
myext.sql: myext.sql.in some_command installcheck: myext.sql
The script exits with non-zero value in case of test failed. In this case, if files regression.diff and regression.out are produced (as pg_regress does), these files are copied to the local directory where the script is run.
The database connection options are similar to the ones in load, with the difference that the variable PGDATABASE doesn't influence the database name.
See the install command for details about the command arguments.
At the time of writing, pg_regress on Debian and derivatives is affected by bug #554166 which makes HOST selection impossible.
Remove a distribution from the system.
pgxn uninstall [--help] [--stable | --testing | --unstable] [--pg_config PROG] [--make PROG] [--sudo [PROG] | --nosudo] SPEC
The command does the opposite of the install command, removing a distribution's files from the system. It doesn't issue any command to the databases where the distribution's extensions may have been loaded: you should first drop the extension (the unload command can do this).
The distribution should match what installed via the install command.
See the install command for details about the command arguments.
Load the extensions included in a distribution into a database. The distribution must be already installed in the system, e.g. via the install command.
pgxn load [--help] [--stable | --testing | --unstable] [-d DBNAME] [-h HOST] [-p PORT] [-U NAME] [--pg_config PATH] [--schema SCHEMA] SPEC [EXT [EXT ...]]
The distribution is specified according to the package specification and can refer to a local directory or file or to an URL. No consistency check is performed between the packages specified in the install and load command: the specifications should refer to compatible packages. The specified distribution is only used to read the metadata: only installed files are actually used to issue database commands.
The database to install into can be specified using options -d/--dbname, -h/--host, -p/--port, -U/--username. The default values for these parameters are the regular system ones and can be also set using environment variables PGDATABASE, PGHOST, PGPORT, PGUSER.
The command supports also a --pg_config option that can be used to specify an alternative pg_config to use to look for installation scripts: you may need to specify the parameter if there are many PostgreSQL installations on the system, and should be consistent to the one specified in the install command.
If the specified database version is at least PostgreSQL 9.1, and if the extension specifies a .control file, it will be loaded using the CREATE EXTENSION command, otherwise it will be loaded as a loose set of objects. For more information see the extensions documentation.
The command is based on the 'provides' section of the distribution's META.json: if a SQL file is specified, that file will be used to load the extension. Note that loading is only attempted if the file extension is .sql: if it's not, we assume that the extension is not really a PostgreSQL extension (it may be for instance a script). If no file is specified, a file named extension.sql will be looked for in a few directories under the PostgreSQL shared directory and it will be loaded after an user confirmation.
If the distribution provides more than one extension, the extensions are loaded in the order in which they are specified in the provides section of the META.json file. It is also possible to load only a few of the extensions provided, specifying them after SPEC: the extensions will be loaded in the order specified.
If a SCHEMA is specified, the extensions are loaded in the provided schema. Note that if CREATE EXTENSION is used, the schema is directly supported; otherwise the .sql script loaded will be patched to create the objects in the provided schema (a confirmation will be asked before attempting loading).
Unload a distribution's extensions from a database.
pgxn unload [--help] [--stable | --testing | --unstable] [-d DBNAME] [-h HOST] [-p PORT] [-U NAME] [--pg_config PATH] [--schema SCHEMA] SPEC [EXT [EXT ...]]
The command does the opposite of the load command: it drops a distribution extensions from the specified database, either issuing DROP EXTENSION commands or running uninstall scripts eventually provided.
For every extension specified in the 'provides' section of the distribution META.json, the command will look for a file called uninstall_file.sql where file.sql is the file specified. If no file is specified, extension.sql is assumed. If a file with extension different from .sql is specified, it is assumed that the extension is not a PostgreSQL extension so unload is not performed.
If a SCHEMA is specified, the uninstall script will be patched to drop the objects in the selected schema. However, if the extension was loaded via CREATE EXTENSION, the server will be able to figure out the correct schema itself, so the option will be ignored.
If the distribution specifies more than one extension, they are unloaded in reverse order respect to the order in which they are specified in the META.json file. It is also possible to unload only a few of the extensions provided, specifying them after SPEC: the extensions will be unloaded in the order specified.
See the load command for details about the command arguments.
Download a distribution from the network.
pgxn download [--help] [--stable | --testing | --unstable] [--target PATH] SPEC
The distribution is specified according to the package specification and can be represented by an URL. The file is saved in the current directory with name usually distribution-version.zip. If a file with the same name exists, a suffix -1, -2 etc. is added to the name, before the extension. A different directory or name can be specified using the --target option.
Search in the extensions available on PGXN.
pgxn search [--help] [--dist | --ext | --docs] TERM [TERM ...]
The command prints on stdout a list of packages and version matching TERM. By default the search is performed in the documentation: alternatively the distributions (using the --dist option) or the extensions (using the --ext option) can be searched.
$ pgxn search --dist integer tinyint 0.1.1 Traditionally, PostgreSQL core has a policy not to have 1 byte *integer* in it. With this module, you can define 1 byte *integer* column on your tables, which will help query performances and... check_updates 1.0.0 ... test2 defined as: CREATE TABLE test2(a *INTEGER*, b *INTEGER*, c *INTEGER*, d *INTEGER*); To make a trigger allowing updates only when c becomes equal to 5: CREATE TRIGGER c_should_be_5 BEFORE UPDATE ON... ssn 1.0.0 INSERT INTO test VALUES('124659876'); The output is always represented using the format with dashes, i.e: 123-45-6789 124-65-9876 Internals: The type is stored as a 4 bytes *integer*.
The search will return all the matches containing any of TERM. In order to search for items containing more than one word, join the word into a single token. For instance to search for items containing the terms "double precision" or the terms "floating point" use:
$ pgxn search "double precision" "floating point" semver 0.2.2 ... to semver semver(12.0::real) 12.0.0semver(*double precision*) Cast *double precision* to semver semver(9.2::*double precision*) 9.2.0semver(integer) Cast integer to semver semver(42::integer)... saio 0.0.1 Defaults to true. saio_seed A *floating point* seed for the random numbers generator. saio_equilibrium_factor Scaling factor for the query size, determining the number of loops before equilibrium is... pgTAP 0.25.0 ... ) casts_are( casts ) SELECT casts_are( ARRAY[ 'integer AS *double precision*', 'integer AS reltime', 'integer AS numeric', -- ...
Print information about a distribution obtained from PGXN.
pgxn info [--help] [--stable | --testing | --unstable] [--details | --meta | --readme | --versions] SPEC
The distribution is specified according to the package specification. It cannot be a local dir or file nor an URL. The command output is a list of values obtained by the distribution's META.json file, for example:
$ pgxn info pair name: pair abstract: A key/value pair data type description: This library contains a single PostgreSQL extension, a key/value pair data type called “pair”, along with a convenience function for constructing key/value pairs. maintainer: David E. Wheeler <david@j...y.com> license: postgresql release_status: stable version: 0.1.2 date: 2011-04-20T23:47:22Z sha1: 9988d7adb056b11f8576db44cca30f88a08bd652 provides: pair: 0.1.2
Alternatively the raw META.json (using the --meta option) or the distribution README (using the --readme option) can be obtained.
Using the --versions option, the command prints a list of available versions for the specified distribution, together with their release status. Only distributions respecting SPEC and the eventually specified release status options are printed, for example:
$ pgxn info --versions 'pair<0.1.2' pair 0.1.1 stable pair 0.1.0 stable
Return information about the available mirrors.
pgxn mirror [--help] [--detailed] [URI]
If no URI is specified, print a list of known mirror URIs. Otherwise print details about the specified mirror. It is also possible to print details for all the known mirrors using the --detailed option.
Display help and other program information.
pgxn help [--help] [--all | --libexec | CMD]
Without options show the same information obtained by pgxn --help, which includes a list of builtin commands. With the --all option print the complete list of commands installed in the system.
The option --libexec prints the full path of the directory containing the external commands scripts: see Extending PGXN client for more information.
pgxn help CMD is an alias for pgxn CMD --help.