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From: Bruce Momjian <pgman@candle.pha.pa.us>
Message-Id: <200304251511.h3PFBg314483@candle.pha.pa.us>
Subject: Re: point-in-time recovery
In-Reply-To: <200304252039.31100.mallah@trade-india.com>
To: Rajesh Kumar Mallah <mallah@trade-india.com>
Date: Fri, 25 Apr 2003 11:11:42 -0400 (EDT)
Cc: pgsql-admin@postgresql.org
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Rajesh Kumar Mallah wrote:
> On Friday 25 Apr 2003 8:17 pm, Bruce Momjian wrote:
> > Rajesh Kumar Mallah wrote:
> > > Thanks for responding , but i still have
> > > more to discuss.
> > >
> > > On Friday 25 Apr 2003 7:47 pm, Bruce Momjian wrote:
> > > > Rajesh Kumar Mallah wrote:
> > > > > What is this PITR anyway ?
> > > > >
> > > > > when it comes will i be able to
> > > > >
> > > > > 1. reduce by pg_dump times ?
> > > > > 2. can afford to run pg_dump less frequently ?
> > > > > 3. Will be able to rollback committed transactions of past 5 mins?
> > > >
> > > > You can do a dump,
> > >
> > > Do u mean pg_dump here, or some special command
> > > thats doing a quick snapshot dump?
> >
> > You do one pg_dump, the start PITR logging.
> 
> I dunno Abt the general case but we have seen
> more instances of data loss by our own actions  (faulty SQL eg)
> rather than HW's or postgresql's 
> 
> Say for my live database.
> Say i start my pg_dump at 5:00p and it finishes say by 5:30p
> then i give the command for PITR logging at 5:31
> 
> Then i accidently delete at say 9pm
> 
> Then am i expected to :
> 1. restore the snapshot of 5:00 pm
> 2. ROLL FORWARD using PITR log till 8:59 or so
>    using some special command ?
> 
> In that case what happens to the transactions from 5:00pm
> to 5:30 pm which were not captured in the pg_dump nor in the
> PITR log?

You have to start PITR logging probably before the pg_dump so there will
be some overlap, but the system will know how to handle it.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
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