Re: pg_xlog - Mailing list pgsql-general

From Bruce Momjian
Subject Re: pg_xlog
Date
Msg-id 200411031920.iA3JK6625785@candle.pha.pa.us
Whole thread Raw
In response to pg_xlog  (Reynard Hilman <reynardmh@lightsky.com>)
List pgsql-general
Reynard Hilman wrote:
>
> Hi,
>
> Is there a way to translate information in pg_xlog files to a more
> readable format?
> Basically we have someone accidentally emptied a text column containing
> quite a large amount of text, and unfortunately have no backups. I know
> the pg_xlog is for WAL, and probably is not the proper way to restore a
> lost data. but I find some of the text in one of the files in pg_xlog
> directory. I can get the text part but there are also non text
> characters. So just wondering if there is a way to interpret the non
> text characters.

No way to dump them.  If you haven't vacuumed the data is still there
but just not visible because the transaction id that delete them is
marked as commited.  If you can undo that or hack the code so delete
rows are visible you would see them.  Such skills are quite complex,
however.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

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