Waiting for PostgreSQL 19 – new pg_get_*_ddl() functions

On 5th of April 2026, Andrew Dunstan committed patch:

Add pg_get_database_ddl() function
 
Add a new SQL-callable function that returns the DDL statements needed
to recreate a database. It takes a regdatabase argument and an optional
VARIADIC text argument for options that are specified as alternating
name/value pairs. The following options are supported: pretty (boolean)
for formatted output, owner (boolean) to include OWNER and tablespace
(boolean) to include TABLESPACE. The return is one or multiple rows
where the first row is a CREATE DATABASE statement and subsequent rows are
ALTER DATABASE statements to set some database properties.
 
The caller must have CONNECT privilege on the target database.
 
Author: Akshay Joshi <akshay.joshi@enterprisedb.com>
Co-authored-by: Andrew Dunstan <andrew@dunslane.net>
Co-authored-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Quan Zongliang <quanzongliang@yeah.net>
Discussion: https://postgr.es/m/CANxoLDc6FHBYJvcgOnZyS+jF0NUo3Lq_83-rttBuJgs9id_UDg@mail.gmail.com
Discussion: https://postgr.es/m/e247c261-e3fb-4810-81e0-a65893170e94@dunslane.net

and 2nd patch:

Add pg_get_role_ddl() function
 
Add a new SQL-callable function that returns the DDL statements needed
to recreate a role. It takes a regrole argument and an optional VARIADIC
text argument for options that are specified as alternating name/value
pairs. The following options are supported: pretty (boolean) for
formatted output and memberships (boolean) to include GRANT statements
for role memberships and membership options. The return is one or
multiple rows where the first row is a CREATE ROLE statement and
subsequent rows are ALTER ROLE statements to set some role properties.
Password information is never included in the output.
 
The caller must have SELECT privilege on pg_authid.
 
Author: Mario Gonzalez <gonzalemario@gmail.com>
Author: Bryan Green <dbryan.green@gmail.com>
Co-authored-by: Andrew Dunstan <andrew@dunslane.net>
Co-authored-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Quan Zongliang <quanzongliang@yeah.net>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/4c5f895e-3281-48f8-b943-9228b7da6471@gmail.com
Discussion: https://postgr.es/m/e247c261-e3fb-4810-81e0-a65893170e94@dunslane.net

and then 3rd patch:

Add pg_get_tablespace_ddl() function
 
Add a new SQL-callable function that returns the DDL statements needed
to recreate a tablespace. It takes a tablespace name or OID and an
optional VARIADIC text argument for options that are specified as
alternating name/value pairs. The following options are supported: pretty
(boolean) for formatted output and owner (boolean) to include OWNER.
(It includes two variants because there is no regtablespace pseudotype.)
The return is one or multiple rows where the first row is a CREATE
TABLESPACE statement and subsequent rows are ALTER TABLESPACE statements
to set some tablespace properties.
 
The caller must have SELECT privilege on pg_tablespace.
 
get_reloptions() in ruleutils.c is made non-static so it can be called
from the new ddlutils.c file.
 
Author: Nishant Sharma <nishant.sharma@enterprisedb.com>
Author: Manni Wood <manni.wood@enterprisedb.com>
Co-authored-by: Andrew Dunstan <andrew@dunslane.net>
Co-authored-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAKWEB6rmnmGKUA87Zmq-s=b3Scsnj02C0kObQjnbL2ajfPWGEw@mail.gmail.com
Discussion: https://postgr.es/m/e247c261-e3fb-4810-81e0-a65893170e94@dunslane.net

Continue reading Waiting for PostgreSQL 19 – new pg_get_*_ddl() functions

Waiting for PostgreSQL 19 – Add non-text output formats to pg_dumpall

On 26th of February 2026, Andrew Dunstan committed patch:

Add non-text output formats to pg_dumpall
 
pg_dumpall can now produce output in custom, directory, or tar formats
in addition to plain text SQL scripts. When using non-text formats,
pg_dumpall creates a directory containing:
- toc.glo: global data (roles and tablespaces) in custom format
- map.dat: mapping between database OIDs and names
- databases/: subdirectory with per-database archives named by OID
 
pg_restore is extended to handle these pg_dumpall archives, restoring
globals and then each database. The --globals-only option can be used
to restore only the global objects.
 
This enables parallel restore of pg_dumpall output and selective
restoration of individual databases from a cluster-wide backup.
 
Author: Mahendra Singh Thalor <mahi6run@gmail.com>
Co-Author: Andrew Dunstan <andrew@dunslane.net>
Reviewed-By: Tushar Ahuja <tushar.ahuja@enterprisedb.com>
Reviewed-By: Jian He <jian.universality@gmail.com>
Reviewed-By: Vaibhav Dalvi <vaibhav.dalvi@enterprisedb.com>
Reviewed-By: Srinath Reddy <srinath2133@gmail.com>
Discussion: https://postgr.es/m/cb103623-8ee6-4ba5-a2c9-f32e3a4933fa@dunslane.net

Continue reading Waiting for PostgreSQL 19 – Add non-text output formats to pg_dumpall

pg_dump speed across versions

Got interested recently in speed of pg_dump. Specifically, if, over the years, it has became faster, and if yes, how much.

Couple of years ago I was in position where we needed to run pg_dump, and found some inefficiencies, which got later patched. This was around the version 12. So, how does the situation look now? Interestingly, not so great…

Continue reading pg_dump speed across versions

Waiting for PostgreSQL 18 – Non text modes for pg_dumpall, correspondingly change pg_restore

On 4th of April 2025, Andrew Dunstan committed patch:

Non text modes for pg_dumpall, correspondingly change pg_restore
 
pg_dumpall acquires a new -F/--format option, with the same meanings as
pg_dump. The default is p, meaning plain text. For any other value, a
directory is created containing two files, globals.data and map.dat. The
first contains SQL for restoring the global data, and the second
contains a map from oids to database names. It will also contain a
subdirectory called databases, inside which it will create archives in
the specified format, named using the database oids.
 
In these casess the -f argument is required.
 
If pg_restore encounters a directory containing globals.dat, and no
toc.dat, it restores the global settings and then restores each
database.
 
pg_restore acquires two new options: -g/--globals-only which suppresses
restoration of any databases, and --exclude-database which inhibits
restoration of particualr database(s) in the same way the same option
works in pg_dumpall.
 
Author: Mahendra Singh Thalor <mahi6run@gmail.com>
Co-authored-by:  Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: jian he <jian.universality@gmail.com>
Reviewed-by: Srinath Reddy <srinath2133@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/cb103623-8ee6-4ba5-a2c9-f32e3a4933fa@dunslane.net

Continue reading Waiting for PostgreSQL 18 – Non text modes for pg_dumpall, correspondingly change pg_restore

Waiting for 9.3 – Add parallel pg_dump option.

On 24th of March, Andrew Dunstan committed patch:

Add parallel pg_dump option.
 
New infrastructure is added which creates a set number of workers
(threads on Windows, forked processes on Unix). Jobs are then
handed out to these workers by the master process as needed.
pg_restore is adjusted to use this new infrastructure in place of the
old setup which created a new worker for each step on the fly. Parallel
dumps acquire a snapshot clone in order to stay consistent, if
available.
 
The parallel option is selected by the -j / --jobs command line
parameter of pg_dump.
 
Joachim Wieland, lightly editorialized by Andrew Dunstan.

Continue reading Waiting for 9.3 – Add parallel pg_dump option.

Parallel dumping of databases

Some time ago I wrote a piece on speeding up dump/restore process using custom solution that was parallelizing process.

Later on I wrote some tools (“fast dump and restore") to do it in more general way.

But all of them had a problem – to get consistent dump you need to stop all concurrent access to your database. Why, and how to get rid of this limitation?

Continue reading Parallel dumping of databases

Command line tools? In XXI century? No way! Yes way!

So, you just installed your PostgreSQL, and you have no idea how to use it – there is no icon in the menu of your OS, so how can you use it? Well, with the dreadful command line.

Of course – some people will never get used to textual programs. They need a GUI. That's fine. Not understandable for me, but who am I to judge. But knowing at least a basic things about standard command line tools for PostgreSQL can save you a lot of headache in some cases. Plus – you always have them so these are treated as default programs to use.

Continue reading Command line tools? In XXI century? No way! Yes way!

Waiting for 9.2 – excluding data of table from dump

On 14h of December, Andrew Dunstan committed patch:

Add --exclude-table-data option to pg_dump.
 
Andrew Dunstan, reviewed by Josh Berkus, Robert Haas and Peter Geoghegan.
 
This allows dumping of a table definition but not its data, on a per table basis.
Table name patterns are supported just as for --exclude-table.

Continue reading Waiting for 9.2 – excluding data of table from dump