Ubuntu Manpage: PGObject::Util::DBAdmin - PostgreSQL Database Management Facilities for PGObject

name
version
synopsis
properties
global variables
subroutines/methods
capturing
author
bugs
support
acknowledgements
license and copyright

oracular (3) PGObject::Util::DBAdmin.3pm.gz

Provided by: libpgobject-util-dbadmin-perl_1.6.1-1_all

NAME

       PGObject::Util::DBAdmin - PostgreSQL Database Management Facilities for PGObject

VERSION

       version 1.6.1

SYNOPSIS

       This module provides an interface to the basic Postgres db manipulation utilities.

        my $db = PGObject::Util::DBAdmin->new(
           connect_data => {
              user     => 'postgres',
              password => 'mypassword',
              host     => 'localhost',
              port     => '5432',
              dbname   => 'mydb'
           }
        );

        my @dbnames = $db->list_dbs(); # like psql -l

        $db->create(); # createdb
        $db->run_file(file => 'sql/initial_schema.sql'); # psql -f

        my $filename = $db->backup(format => 'c'); # pg_dump -Fc

        my $db2 = PGObject::Util::DBAdmin->new($db->export, (dbname => 'otherdb'));

        my $db3 = PGObject::Util::DBAdmin->new(
           connect_data => {
              service     => 'zephyr',
              sslmode     => 'require',
              sslkey      => "$HOME/.postgresql/postgresql.key",
              sslcert     => "$HOME/.postgresql/postgresql.crt",
              sslpassword => 'your-sslpassword',
           }
        );

PROPERTIES

connect_data
Contains a hash with connection parameters; see the PostgreSQL documentation
<https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS> for supported
parameters.

The usual parameters are:

• user

• password

• dbname

• host

• port

Please note that the key "requiressl" is deprecated in favor of "sslmode" and isn't supported.

username (deprecated)
The username used to authenticate with the PostgreSQL server.

password (deprecated)
The password used to authenticate with the PostgreSQL server.

host (deprecated)
In PostgreSQL, this can refer to the hostname or the absolute path to the directory where the UNIX
sockets are set up.

port (deprecated)
Default '5432'

dbname (deprecated)
The database name to create or connect to.

stderr
When applicable, the stderr output captured from any external commands (for example createdb or
pg_restore) run during the previous method call. See notes in "CAPTURING".

stdout
When applicable, the stdout output captured from any external commands (for example createdb or
pg_restore) run during the previous method call. See notes in "CAPTURING".

logger
Provides a reference to the logger associated with the current instance. The logger uses "ref $self" as
its category, eliminating the need to create new loggers when deriving from this class.

If you want to override the logger-instantiation behaviour, please implement the "_build_logger" builder
method in your derived class.

GLOBAL VARIABLES

   %helper_paths
       This hash variable contains as its keys the names of the PostgreSQL helper executables "psql", "dropdb",
       "pg_dump", etc. The values contain the paths at which the executables to be run are located. The default
       values are the names of the executables only, allowing them to be looked up in $PATH.

       Modification of the values in this variable are the strict realm of applications. Libraries using this
       library should defer potential required modifications to the applications based upon them.

SUBROUTINES/METHODS

new
Creates a new db admin object for manipulating databases.

BUILDARGS
Compensates for the legacy invocation with the "username", "password", "host", "port" and "dbname"
parameters.

verify_helpers( [ helpers => [...]], [operations => [...]])
Verifies ability to execute (external) helper applications by method name (through the "operations"
argument) or by external helper name (through the "helpers" argument). Returns a hash ref with each key
being the name of a helper application (see "helpers" below) with the values being a boolean indicating
whether or not the helper can be successfully executed.

Valid values in the array referenced by the "operations" parameter are "create", "run_file", "backup",
"backup_globals", "restore" and "drop"; the methods this module implements with the help of external
helper programs. (Other values may be passed, but unsupported values aren't included in the return
value.)

Valid values in the array referenced by the "helpers" parameter are the names of the PostgreSQL helper
programs "createdb", "dropdb", "pg_dump", "pg_dumpall", "pg_restore" and "psql". (Other values may be
passed, but unsupported values will not be included in the return value.)

When no arguments are passed, all helpers will be tested.

Note: "verify_helpers" is a class method, meaning it wants to be called as
"PGObject::Util::DBAdmin-"verify_helpers()>.

export
Exports the database parameters as a list so it can be used to create another object.

connect($options)
Connects to the database using DBI and returns a database connection.

Connection options may be specified in the $options hashref.

server_version([$dbname])
Returns a version string (like 9.1.4) for PostgreSQL. Croaks on error.

When a database name is specified, uses that database to connect to, using the credentials specified in
the instance.

If no database name is specified, 'template1' is used.

list_dbs([$dbname])
Returns a list of db names.

When a database name is specified, uses that database to connect to, using the credentials specified in
the instance.

If no database name is specified, 'template1' is used.

create
Creates a new database.

Croaks on error, returns true on success.

Supported arguments:

copy_of
Creates the new database as a copy of the specified one (using it as a template). Optional parameter.
Default is to create a database without a template.

run_file
Run the specified file on the db.

After calling this method, STDOUT and STDERR output from the external utility which runs the file on the
database are available as properties $db->stdout and $db->stderr respectively.

Croaks on error. Returns true on success.

Recognized arguments are:

file
Path to file to be run. This is a mandatory argument.

vars
A hash reference containing "psql"-variables to be passed to the script being executed. Running:

$dbadmin->run_file(file => '/tmp/pg.sql', vars => { schema => 'xyz' });

Is equivalent to starting the file "/tmp/pg.sql" with the command

\set schema xyz

To undefine a variable, associate the variable name (hash key) with the value "undef".

stdout_log
Provided for legacy compatibility. Optional argument. The full path of a file to which STDOUT from
the external psql utility will be appended.

errlog
Provided for legacy compatibility. Optional argument. The full path of a file to which STDERR from
the external psql utility will be appended.

backup
Creates a database backup file.

After calling this method, STDOUT and STDERR output from the external utility which runs the file on the
database are available as properties $db->stdout and $db->stderr respectively.

Unlinks the output file and croaks on error.

Returns the full path of the file containining the backup.

Accepted parameters:

format
The specified format, for example c for custom. Defaults to plain text.

file
Full path of the file to which the backup will be written. If the file does not exist, one will be
created with umask 0600. If the file exists, it will be overwritten, but its permissions will not be
changed.

If undefined, a file will be created using File::Temp having umask 0600.

tempdir
The directory in which to write the backup file. Optional parameter. Uses File::Temp default if not
defined. Ignored if file parameter is given.

compress
Optional parameter. Specifies the compression level to use and is passed to the underlying pg_dump
command. Default is no compression.

backup_globals
This creates a file containing a plain text dump of global (inter-db) objects, such as users and
tablespaces. It uses pg_dumpall to do this.

Being a plain text file, it can be restored using the run_file method.

Unlinks the output file and croaks on error.

Returns the full path of the file containining the backup.

Accepted parameters:

If undefined, a file will be created using File::Temp having umask 0600.

tempdir
The directory in which to write the backup file. Optional parameter. Uses File::Temp default if not
defined. Ignored if file parameter is given.

restore
Restores from a saved file. Must pass in the file name as a named argument.

After calling this method, STDOUT and STDERR output from the external restore utility are available as
properties $db->stdout and $db->stderr respectively.

Croaks on error. Returns true on success.

Recognized arguments are:

file
Path to file which will be restored to the database. Required.

format
The file format, for example c for custom. Defaults to plain text.

drop
Drops the database. This is not recoverable. Croaks on error, returns true on success.

is_ready
Drops the database. This is not recoverable. Croaks on error, returns true on success.

CAPTURING

       This module uses "Capture::Tiny" to run extenal commands and capture their output, which is made
       available through the "stderr" and "stdout" properties.

       This capturing does not work if Perl's standard "STDOUT" or "STDERR" filehandles have been localized. In
       this situation, the localized filehandles are captured, but external system calls are not affected by the
       localization, so their output is sent to the original filehandles and is not captured.

       See the "Capture::Tiny" documentation for more details.

AUTHOR

       Chris Travers, "<chris at efficito.com>"

BUGS

       Please report any bugs or feature requests to "bug-pgobject-util-dbadmin at rt.cpan.org", or through the
       web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=PGObject-Util-DBAdmin>.  I will be
       notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

       You can find documentation for this module with the perldoc command.

           perldoc PGObject::Util::DBAdmin

       You can also look for information at:

       •   RT: CPAN's request tracker (report bugs here)

           <http://rt.cpan.org/NoAuth/Bugs.html?Dist=PGObject-Util-DBAdmin>

       •   AnnoCPAN: Annotated CPAN documentation

           <http://annocpan.org/dist/PGObject-Util-DBAdmin>

       •   CPAN Ratings

           <http://cpanratings.perl.org/d/PGObject-Util-DBAdmin>

       •   Search CPAN

           <http://search.cpan.org/dist/PGObject-Util-DBAdmin/>

ACKNOWLEDGEMENTS

LICENSE AND COPYRIGHT

       Copyright 2014-2020 Chris Travers.

       This program is distributed under the (Revised) BSD License:
       <http://www.opensource.org/licenses/BSD-3-Clause>

       Redistribution and use in source and binary forms, with or without modification, are permitted provided
       that the following conditions are met:

       * Redistributions of source code must retain the above copyright notice, this list of conditions and the
       following disclaimer.

       * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
       the following disclaimer in the documentation and/or other materials provided with the distribution.

       * Neither the name of Chris Travers's Organization nor the names of its contributors may be used to
       endorse or promote products derived from this software without specific prior written permission.

       THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
       WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
       PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
       ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
       LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
       INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
       TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.