On 15th of March, Robert Haas committed patch: Add simple VACUUM progress reporting. There's a lot more that could be done here yet - in particular, this reports only very coarse-grained information about the index vacuuming phase - but even as it stands, ...

On 9th of March, Robert Haas committed patch: Add a generic command progress reporting facility. Using this facility, any utility command can report the target relation upon which it is operating, if there is one, and up to 10 64-bit counters; the intent of ...

On 23rd of January, Alvaro Herrera committed patch: vacuumdb: enable parallel mode This mode allows vacuumdb to open several server connections to vacuum or analyze several tables simultaneously. Author: Dilip Kumar. Some reworking by Álvaro Herrera Reviewed by: Jeff Janes, Amit Kapila, Magnus Hagander, ...

In release notes to latest release you can find: Fix VACUUM's tests to see whether it can update relfrozenxid (Andres Freund) In some cases VACUUM (either manual or autovacuum) could incorrectly advance a table's relfrozenxid value, allowing tuples to escape freezing, causing those rows ...

Looong time ago, I wrote a piece about removing bloat by moving rows away from the end of table, and vacuuming it. This is/was very slow, and was optimized (to some extent) by Nathan Thom, but his blogpost vanished. Besides, later ...

In previous posts in this series, I talked about how to read EXPLAIN output, and what each line (operation/node) means. Now, in the final post, I will try to explain how it happens that Pg chooses "Operation X" over "Operation Y".

July 6th, 2011 by depesz | Tags: , , , , , , , | 20 comments »

For various reasons, and in various cases, bloat happens. Theoretically autovacuum protects us all, but sometimes it doesn't. Sometimes someone disables it, or mis-configures, or bad planet alignment happens, and we end up in deep bloat. What to do then? Vacuum? ...

Some time ago Joshua Tolley described how to reduce bloat from tables without locking (well, some locks are there, but very short, and not really intrusive). Side note: Joshua: big thanks, great idea. Based on his idea and some our research, i ...

Some time ago Josh Berkus wrote about possible changes in VACUUM FULL. Now these changes came to life. By now, I mean 6th of January, when Takahiro Itagaki committed his patch: Log Message: ----------- Support rewritten-based full vacuum as VACUUM FULL. Traditional VACUUM FULL was ...

Yeah. This one patch alone is worth upgrading to 8.4. On 3rd of December Heikki Linnakangas committed his patch. Commit message: Introduce visibility map. The visibility map is a bitmap with one bit per heap page, where a set bit indicates that all ...