Re: Point in Time Recovery

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Zeugswetter Andreas SB SD" <ZeugswetterA(at)spardat(dot)at>
Cc: "Bruce Momjian" <pgman(at)candle(dot)pha(dot)pa(dot)us>, "Mark Kirkwood" <markir(at)coretech(dot)co(dot)nz>, "Simon Riggs" <simon(at)2ndquadrant(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Point in Time Recovery
Date: 2004-07-30 17:04:46
Message-ID: 24226.1091207086@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

"Zeugswetter Andreas SB SD" <ZeugswetterA(at)spardat(dot)at> writes:
> If you use a readable file you will also need a feature for restore
> (or a tool) to create an appropriate pg_control file, or are you
> intending to still require that pg_control be the first file backed
> up.

No, the entire point of this exercise is to get rid of that assumption.
You do need *a* copy of pg_control, but the only reason you'd need to
back it up first rather than later is so that its checkpoint pointer
points to the last checkpoint before the dump starts. Which is the
information we want to put in the archive-label file insted.

If a copy of pg_control were sufficient then I'd be all for using it as
the archive-label file, but it's *not* sufficient because you also need
the ending WAL offset. So we need a different file layout in any case,
and we may as well take some pity on the poor DBA and make the file
easily human-readable.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2004-07-30 18:00:00 Re: Where does the xlateSqlType symbol point to?
Previous Message Bruce Momjian 2004-07-30 16:41:25 Re: pgxs: build infrastructure for extensions v4