Tag: schema

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 psql PROMPT variable for search_path.

On 28th of October 2025, Nathan Bossart committed patch:

Add psql PROMPT variable for search_path.
 
The new %S substitution shows the current value of search_path.
Note that this only works when connected to Postgres v18 or newer,
since search_path was first marked as GUC_REPORT in commit
28a1121fd9.  On older versions that don't report search_path, %S is
replaced with a question mark.
 
Suggested-by: Lauri Siltanen <lauri.siltanen@gmail.com>
Author: Florents Tselai <florents.tselai@gmail.com>
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CANsM767JhTKCRagTaq5Lz52fVwLPVkhSpyD1C%2BOrridGv0SO0A%40mail.gmail.com

Continue reading Waiting for PostgreSQL 19 – Add psql PROMPT variable for search_path.

Waiting for PostgreSQL 15 – Allow publishing the tables of schema.

On 27th of October 2021, Amit Kapila committed patch:

Allow publishing the tables of schema.
 
A new option "FOR ALL TABLES IN SCHEMA" in Create/Alter Publication allows
one or more schemas to be specified, whose tables are selected by the
publisher for sending the data to the subscriber.
 
The new syntax allows specifying both the tables and schemas. For example:
CREATE PUBLICATION pub1 FOR TABLE t1,t2,t3, ALL TABLES IN SCHEMA s1,s2;
OR
ALTER PUBLICATION pub1 ADD TABLE t1,t2,t3, ALL TABLES IN SCHEMA s1,s2;
 
A new system table "pg_publication_namespace" has been added, to maintain
the schemas that the user wants to publish through the publication.
Modified the output plugin (pgoutput) to publish the changes if the
relation is part of schema publication.
 
Updates pg_dump to identify and dump schema publications. Updates the \d
family of commands to display schema publications and \dRp+ variant will
now display associated schemas if any.
 
Author: Vignesh C, Hou Zhijie, Amit Kapila
Syntax-Suggested-by: Tom Lane, Alvaro Herrera
Reviewed-by: Greg Nancarrow, Masahiko Sawada, Hou Zhijie, Amit Kapila, Haiying Tang, Ajin Cherian, Rahila Syed, Bharath Rupireddy, Mark Dilger
Tested-by: Haiying Tang
Discussion: https://www.postgresql.org/message-id/CALDaNm0OANxuJ6RXqwZsM1MSY4s19nuH3734j4a72etDwvBETQ@mail.gmail.com

Continue reading Waiting for PostgreSQL 15 – Allow publishing the tables of schema.

Which schema is using the most disk space?

I was faced with interesting problem. Which schema, in my DB, uses the most disk space? Theoretically it's trivial, we have set of helpful functions:

  • pg_column_size
  • pg_database_size
  • pg_indexes_size
  • pg_relation_size
  • pg_table_size
  • pg_tablespace_size
  • pg_total_relation_size

But in some cases it becomes more of a problem. For example – when you have thousands of tables …

Continue reading Which schema is using the most disk space?

Waiting for 9.5 – Implement IMPORT FOREIGN SCHEMA.

On 10th of July, Tom Lane committed patch:

Implement IMPORT FOREIGN SCHEMA.
 
This command provides an automated way to create foreign table definitions
that match remote tables, thereby reducing tedium and chances for error.
In this patch, we provide the necessary core-server infrastructure and
implement the feature fully in the postgres_fdw foreign-data wrapper.
Other wrappers will throw a "feature not supported" error until/unless
they are updated.
 
Ronan Dunklau and Michael Paquier, additional work by me

Continue reading Waiting for 9.5 – Implement IMPORT FOREIGN SCHEMA.

Waiting for 9.1 – EXTENSIONS

On 8th of February, Tom Lane committed patch:

Core support for "extensions", which are packages of SQL objects.
 
This patch adds the server infrastructure to support extensions.
There is still one significant loose end, namely how to make it play nice
with pg_upgrade, so I am not yet committing the changes that would make
all the contrib modules depend on this feature.
 
In passing, fix a disturbingly large amount of breakage in
AlterObjectNamespace() and callers.
 
Dimitri Fontaine, reviewed by Anssi Kääriäinen,
Itagaki Takahiro, Tom Lane, and numerous others

Continue reading Waiting for 9.1 – EXTENSIONS