| Lists: | pgsql-general |
|---|
| From: | Geoffrey <lists(at)serioustechnology(dot)com> |
|---|---|
| To: | PostgreSQL List <pgsql-general(at)postgresql(dot)org> |
| Subject: | WAL file question |
| Date: | 2009-11-17 13:39:33 |
| Message-ID: | 4B02A795.9020202@serioustechnology.com |
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| Lists: | pgsql-general |
listing of wal file time stamps for one of our production databases:
Nov 17 06:22 000000010000006100000013
Nov 17 06:42 000000010000006100000014
Nov 17 07:02 000000010000006100000015
Nov 17 07:22 000000010000006100000016
Nov 17 07:42 000000010000006100000017
Nov 17 08:02 000000010000006100000018
Nov 17 08:22 000000010000006100000019
Nov 17 08:34 000000010000006100000012
I would expect that these things are sequential, yet the file that I
would think would be the oldest (000000010000006100000012) has the
latest time stamp.
What am I missing?
--
Until later, Geoffrey
Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety.
- Benjamin Franklin
| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Geoffrey <lists(at)serioustechnology(dot)com> |
| Cc: | PostgreSQL List <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: WAL file question |
| Date: | 2009-11-17 14:52:37 |
| Message-ID: | 28093.1258469557@sss.pgh.pa.us |
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| Lists: | pgsql-general |
Geoffrey <lists(at)serioustechnology(dot)com> writes:
> listing of wal file time stamps for one of our production databases:
> Nov 17 06:22 000000010000006100000013
> Nov 17 06:42 000000010000006100000014
> Nov 17 07:02 000000010000006100000015
> Nov 17 07:22 000000010000006100000016
> Nov 17 07:42 000000010000006100000017
> Nov 17 08:02 000000010000006100000018
> Nov 17 08:22 000000010000006100000019
> Nov 17 08:34 000000010000006100000012
> I would expect that these things are sequential, yet the file that I
> would think would be the oldest (000000010000006100000012) has the
> latest time stamp.
> What am I missing?
Most of those are probably old files that have been renamed into place
for future use --- and the renamer doesn't really worry about reusing
old files in order. I suspect ...12 is the only one that's live.
A look at pg_controldata output would help you check that.
regards, tom lane
| From: | Geoffrey <lists(at)serioustechnology(dot)com> |
|---|---|
| To: | PostgreSQL List <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: WAL file question |
| Date: | 2009-11-17 15:36:38 |
| Message-ID: | 4B02C306.5030502@serioustechnology.com |
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| Lists: | pgsql-general |
Tom Lane wrote:
> Geoffrey <lists(at)serioustechnology(dot)com> writes:
>> listing of wal file time stamps for one of our production databases:
>> Nov 17 06:22 000000010000006100000013
>> Nov 17 06:42 000000010000006100000014
>> Nov 17 07:02 000000010000006100000015
>> Nov 17 07:22 000000010000006100000016
>> Nov 17 07:42 000000010000006100000017
>> Nov 17 08:02 000000010000006100000018
>> Nov 17 08:22 000000010000006100000019
>> Nov 17 08:34 000000010000006100000012
>
>> I would expect that these things are sequential, yet the file that I
>> would think would be the oldest (000000010000006100000012) has the
>> latest time stamp.
>
>> What am I missing?
>
> Most of those are probably old files that have been renamed into place
> for future use --- and the renamer doesn't really worry about reusing
> old files in order. I suspect ...12 is the only one that's live.
> A look at pg_controldata output would help you check that.
>
> regards, tom lane
Thanks Tom.
--
Until later, Geoffrey
Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety.
- Benjamin Franklin