Tag: postgresql

Waiting for 9.1 – Add UNIQUE/PRIMARY KEY with index

On 25th of January, Tom Lane committed patch:

Implement ALTER TABLE ADD UNIQUE/PRIMARY KEY USING INDEX.
 
This feature allows a UNIQUE OR pkey CONSTRAINT TO be created USING an
already-existing UNIQUE INDEX.  While the CONSTRAINT isn't very
functionally different from the bare index, it's nice TO be able TO do that
FOR documentation purposes.  The main advantage OVER just issuing a plain
ALTER TABLE ADD UNIQUE/PRIMARY KEY IS that the INDEX can be created WITH
CREATE INDEX CONCURRENTLY, so that there IS NOT a long INTERVAL WHERE the
TABLE IS locked against updates.
 
ON the way, refactor SOME OF the code IN DefineIndex() AND index_create()
so that we don't have to pass through those functions in order to create
the index constraint's catalog entries.  Also, IN parse_utilcmd.c, pass
around the ParseState pointer IN struct CreateStmtContext TO save ON
notation, AND ADD error location pointers TO SOME error reports that didn't
have one before.
 
Gurjeet Singh, reviewed by Steve Singer and Tom Lane

Continue reading Waiting for 9.1 – Add UNIQUE/PRIMARY KEY with index

OmniPITR – update

As of yesterday OmniPITR got following changes/fixes:

  1. Fixed bug which caused immediate finish request be treated the same as smart finish request.
  2. Fixed problem with using omnipitr-backup-slave on PostgreSQL 9.0 slave, which is using streaming replication.
  3. Added option to omnipitr-restore, so that you can now use it for streaming-replication slaves

I'm very ashamed of the first thing (smart/immediate finish request), as it was simply my lack of test.

Second thing – the problem was that with streaming replication slave behaves a bit differently than normally, and so the backup procedure had to be modified.

As for third – restore command in streaming replication environment has to behave differently than normal restore command – i.e. it should finish, with error, as soon as it will be called for wal file that does not exist in wal archive. Which is direct opposite of what should be done normally.

Now, omnipitr-restore got switch (-sr) to make it work correctly in SR situation.

Links for svn/docs are listed on project page.

Waiting for 9.1 – sepgsql

On 24th of January, Robert Haas committed very important patch:

sepgsql, an SE-Linux integration for PostgreSQL
 
This is still pretty rough - among other things, the documentation
needs work, and the messages need a visit from the style police -
but this gets the basic framework in place.
 
KaiGai Kohei

Now, In this place I usually show you what it is all about, but it's not going to happen with this patch. Reason is very simple – I know that it's important, and that it integrates PostgreSQL with SE/Linux, but since I never played with SE/Linux – I cannot really show you anything in here.

But – if you know anything about SE/Linux and sepgsql, I would like to ask you to describe this extension so that even I could understand it.

Sorry – I know I should put more in here, but it simply is so far above my knowledge limits, it would take me too long time to get through documentation for SE/Linux and sepgsql.

For now – if you want to know more – simply check the docs.

Waiting for 9.1 – pg_basebackup

On 23rd of January, Magnus Hagander committed patch which adds:

Add pg_basebackup tool for streaming base backups
 
This tool makes it possible to do the pg_start_backup/
copy files/pg_stop_backup step in a single command.
 
There are still some steps to be done before this is a
complete backup solution, such as the ability to stream
the required WAL logs, but it's still usable, and
could do with some buildfarm coverage.
 
In passing, make the checkpoint request optionally
fast instead of hardcoding it.
 
Magnus Hagander, reviewed by Fujii Masao and Dimitri Fontaine

Continue reading Waiting for 9.1 – pg_basebackup

Tablespaces support for omnipitr-backup-*

Really cool news. Thanks to sponsoring from AWeber.com, and code by Brian Dunavant OmniPITR has now support for additional tablespaces in backup creation.

This works on both master and slave, and happens automatically without any kind of user interaction or changing options – OmniPITR simply detects if you have additional tablespaces and backs them up to data tarball.

More details are places in TABLESPACES part of omnipitr-backup-* docs.

Waiting for 9.1 – Unlogged tables

On 29th of December, Robert Haas committed interesting patch, which does:

Support unlogged tables.
 
The contents of an unlogged table aren't WAL-logged; thus, they are not
available on standby servers and are truncated whenever the database
system enters recovery.  Indexes on unlogged tables are also unlogged.
Unlogged GiST indexes are not currently supported.

(edited commit message, due to this mail.

Continue reading Waiting for 9.1 – Unlogged tables

Two years of explain.depesz.com

First of all – just today I committed patch for Pg::Explain – which is the workhorse behind explain.depesz.com.

This patch fixes calculation of exclusive time for explain nodes, and the best thing about it is – I didn't write it. It's full patch provided by someone else – Filip Rembiałkowski – my former colleague, friend, and PostgreSQL DBA (not olny PG!).

This is (as far as I recall) first patch that was provided to me for this library, and I'm really grateful for the contribution.

New version of Pg::Explain will hit CPAN mirrors shortly (it's already uploaded, now we're waiting for CPAN mirrors to get it).

When I was updating it, I checked state of database. And I learned that explain.depesz.com is over 2 years now! Some stats follow.

Continue reading Two years of explain.depesz.com

Waiting for 9.1 – KNNGIST

On 4th of December, Tom Lane committed really cool patch:

KNNGIST, otherwise known as order-by-operator support for GIST.

This commit represents a rather heavily editorialized version of
Teodor's builtin_knngist_itself-0.8.2 and builtin_knngist_proc-0.8.1
patches.  I redid the opclass API to add a separate Distance method
instead of turning the Consistent method into an illogical mess,
fixed some bit-rot in the rbtree interfaces, and generally worked over
the code style and comments.
 
There's still no non-code documentation to speak of, but I'll work on
that separately.  Some contrib-module changes are also yet to come
(right now, point <-> point is the only KNN-ified operator).
 
Teodor Sigaev and Tom Lane

Continue reading Waiting for 9.1 – KNNGIST

Auto refreshing password file for pgbouncer

As you perhaps know I'm fan of pgbouncer – connection pooling solution for PostgreSQL.

It can do many really cool things, but has one slight issue.

Since it can reuse connections – it has to provide a way to check if user supplied password is correct without consulting database. And it lately (since 9.0 to be exact) became somewhat of a problem.

Continue reading Auto refreshing password file for pgbouncer