Tag: alter

Waiting for PostgreSQL 17 – ALTER TABLE command to change generation expression

On 4th of January 2024, Peter Eisentraut committed patch:

ALTER TABLE command to change generation expression
 
This adds a new ALTER TABLE subcommand ALTER COLUMN ... SET EXPRESSION
that changes the generation expression of a generated column.
 
The syntax is not standard but was adapted from other SQL
implementations.
 
This command causes a table rewrite, using the usual ALTER TABLE
mechanisms.  The implementation is similar to and makes use of some of
the infrastructure of the SET DATA TYPE subcommand (for example,
rebuilding constraints and indexes afterwards).  The new command
requires a new pass in AlterTablePass, and the ADD COLUMN pass had to
be moved earlier so that combinations of ADD COLUMN and SET EXPRESSION
can work.
 
Author: Amul Sul <sulamul@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b94yyJeGA-5M951_Lr+KfZokOp-2kXicpmEhi5FXhBeTog@mail.gmail.com

Continue reading Waiting for PostgreSQL 17 – ALTER TABLE command to change generation expression

Waiting for 9.6 – Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN

On 30th of July, Andrew Dunstan committed patch:

Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN
 
Fabrízio de Royes Mello, reviewed by Payal Singh, Alvaro Herrera and
Michael Paquier.

Continue reading Waiting for 9.6 – Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN

Waiting for 9.5 – Reduce lock levels of some trigger DDL and add FKs

On 5th of April, Simon Riggs committed patch:

Reduce lock levels of some trigger DDL and add FKs
 
Reduce lock levels to ShareRowExclusive for the following SQL
 CREATE TRIGGER (but not DROP or ALTER)
 ALTER TABLE ENABLE TRIGGER
 ALTER TABLE DISABLE TRIGGER
 ALTER TABLE … ADD CONSTRAINT FOREIGN KEY
 
Original work by Simon Riggs, extracted and refreshed by Andreas Karlsson
New test cases added by Andreas Karlsson
Reviewed by Noah Misch, Andres Freund, Michael Paquier and Simon Riggs

Continue reading Waiting for 9.5 – Reduce lock levels of some trigger DDL and add FKs

Waiting for 9.5 – Event Trigger for table_rewrite

On 7th of December, Simon Riggs committed patch:

Event Trigger for table_rewrite
 
Generate a table_rewrite event when ALTER TABLE
attempts to rewrite a table. Provide helper
functions to identify table and reason.
 
Intended use case is to help assess or to react
to schema changes that might hold exclusive locks
for long periods.
 
Dimitri Fontaine, triggering an edit by Simon Riggs
 
Reviewed in detail by Michael Paquier

Continue reading Waiting for 9.5 – Event Trigger for table_rewrite

Waiting for 9.5 – Support ALTER SYSTEM RESET command.

On 2nd of September, Fujii Masao committed patch:

Support ALTER SYSTEM RESET command.
 
This patch allows us to execute ALTER SYSTEM RESET command to
remove the configuration entry from postgresql.auto.conf.
 
Vik Fearing, reviewed by Amit Kapila and me.

Continue reading Waiting for 9.5 – Support ALTER SYSTEM RESET command.

Waiting for 9.5 – Implement ALTER TABLE .. SET LOGGED / UNLOGGED

On 22nd of August, Alvaro Herrera committed patch:

Implement ALTER TABLE .. SET LOGGED / UNLOGGED
 
This enables changing permanent (logged) tables to unlogged and
vice-versa.
 
(Docs for ALTER TABLE / SET TABLESPACE got shuffled in an order that
hopefully makes more sense than the original.)
 
Author: Fabrízio de Royes Mello
Reviewed by: Christoph Berg, Andres Freund, Thom Brown
Some tweaking by Álvaro Herrera

Continue reading Waiting for 9.5 – Implement ALTER TABLE .. SET LOGGED / UNLOGGED

Waiting for 9.4 – Add ALTER SYSTEM command to edit the server configuration file.

On 18th of December, Tatsuo Ishii committed patch:

Add ALTER SYSTEM command to edit the server configuration file.
 
Patch contributed by Amit Kapila. Reviewed by Hari Babu, Masao Fujii,
Boszormenyi Zoltan, Andres Freund, Greg Smith and others.

On the next day, Fujii Masao committed patch:

Add tab completion for ALTER SYSTEM SET in psql.

Continue reading Waiting for 9.4 – Add ALTER SYSTEM command to edit the server configuration file.

Waiting for 9.4 – ALTER TABLE … ALTER CONSTRAINT for FKs

On 28th of June, Simon Riggs committed patch:

ALTER TABLE ... ALTER CONSTRAINT for FKs
 
Allow constraint attributes to be altered,
so the default setting of NOT DEFERRABLE
can be altered to DEFERRABLE and back.
 
Review by Abhijit Menon-Sen

Continue reading Waiting for 9.4 – ALTER TABLE … ALTER CONSTRAINT for FKs

Waiting for 9.2 – More rewrite-less ALTER TABLE ALTER TYPEs

Three patches for you today, all committed by Robert Hass:

  • On 7th of February, patch: 
    Add a transform function for numeric typmod coercisions.
 
This enables ALTER TABLE to skip table and index rebuilds when a column
is changed to an unconstrained numeric, or when the scale is unchanged
and the precision does not decrease.
 
Noah Misch, with a few stylistic changes and a fix for an OID
collision by me.
  • also on 7th, patch: 
    Add a transform function for varbit typmod coercisions.
 
This enables ALTER TABLE to skip table and index rebuilds when the
new type is unconstraint varbit, or when the allowable number of bits
is not decreasing.
 
Noah Misch, with review and a fix for an OID collision by me.
  • and a day later final patch: 
    Add transform functions for various temporal typmod coercisions.
 
This enables ALTER TABLE to skip table and index rebuilds in some cases.
 
Noah Misch, with trivial changes by me.

Continue reading Waiting for 9.2 – More rewrite-less ALTER TABLE ALTER TYPEs