Re: Sizing and striping log area - Mailing list pgsql-general

From Shridhar Daithankar
Subject Re: Sizing and striping log area
Date
Msg-id 3DAD5645.21693.1ADD61@localhost
Whole thread Raw
In response to Re: Sizing and striping log area  ("news.postgresql.org" <brett_elliott@att.net>)
List pgsql-general
On 14 Oct 2002 at 14:40, news.postgresql.org wrote:
> Are they archived like Oracle logs?  Oracle writes to a log area and reads
> from the log area to generate archives.  The archives are then used for
> recovery in case of corruption.  This is important because reading from the
> drive throws off the head used for writing so seeking could be involved
> given this situation where reading and writing happen on the same drive
> concurrently. Oracle minimizes this by filling up, say, 500k of a certain
> disk before writing the logs to the next disk.  Then it reads the 500k of
> logs and moves those to the archive.  But if postgres doesn't use archives
> then this isn't an issue.

As Bruce has pointed out, WALs are recycled currently and archival is added in
7.4(IIRC). However I think postgresql recycles WAL files only after  data is
committed. So at any point of time, if you have your WAL files in physically
consistent state, you can recover from them.

> I realize that you get what you pay for so I'm prepared for the truth. :)

You could have done without that comment.


Bye
 Shridhar

--
Van Roy's Law:    Honesty is the best policy - there's less competition.Van Roy's
Truism:    Life is a whole series of circumstances beyond your control.


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