Re: Tools for dumping pg_xlog, pg_clog, etc?

From: Gerhard Wiesinger <lists(at)wiesinger(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Tools for dumping pg_xlog, pg_clog, etc?
Date: 2007-11-26 06:23:43
Message-ID: Pine.LNX.4.64.0711260716450.1795@bbs.intern
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Hello!

Since the pg_filedump utility manages only the database file I'm currently
writing a pg_xlog/pg_clog viewer.

I'm looking for the documentation in:
// See src/include/access/xlog.h
// See src/include/access/xlog_internal.h
// See src/include/access/xlogdefs.h
// See src/backend/access/transam/xlog.c

// See src/include/access/clog.h
// See src/backend/access/transam/clog.c

// See src/include/access/rmgr.h
// See src/backend/access/transam/rmgr.c

But I'm still having problems to get a suitable output:
1.) pg_xlog:
a.) Reading XLogPageHeaderData or XLogLongPageHeaderData works well
b.) Afterwards a XLogRecord should be expected but the output doesn't look
suitable (e.g. CRC has 000000 in it in different files which is not
suitable)
I'll expect in b.):
* The overall layout of an XLOG record is:
* Fixed-size header (XLogRecord struct)
* rmgr-specific data
* BkpBlock
* backup block data
* BkpBlock
* backup block data
* ...

Any ideas of the correct structure?

2.) pg_clog:
I'm not sure what the correct structures of pg_clog are.
Any ideas?

Thnx.

Ciao,
Gerhard

--
http://www.wiesinger.com/

On Sat, 26 May 2007, Gerhard Wiesinger wrote:

> Hello!
>
> I think I found a proper utility for that: pg_filedump
> http://sources.redhat.com/rhdb/utilities.html
>
> Ciao,
> Gerhard
>
> --
> http://www.wiesinger.com/
>
>
> On Fri, 18 May 2007, Gerhard Wiesinger wrote:
>
>> Hello!
>>
>> Are there any tools available to dump the files of the pg_xlog, pg_clog,
>> ... directories in human readable format to understand how transaction
>> handling is done?
>>
>> Thanx.
>>
>> Ciao,
>> Gerhard
>>
>> --
>> http://www.wiesinger.com/
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 5: don't forget to increase your free space map settings
>>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: Have you checked our extensive FAQ?
>
> http://www.postgresql.org/docs/faq
>

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Simon Riggs 2007-11-26 07:34:23 Re: replication in Postgres
Previous Message Medi Montaseri 2007-11-26 05:24:15 Re: Migrating from 32 to 64 bit