Re: how to determined the recover start point when oracle crash

From: Mark D Powell <>
Date: Wed, 12 Nov 2008 08:16:42 -0800 (PST)
Message-ID: <>

On Nov 11, 9:59 pm, moumouyu <> wrote:
>  Sometimes ,if oracle crash(mediea or instance level) ,we must
> implement some recover .
> As  every one knows ,there are vary SCN in oracle,just like start scn,
> stop scn ,block scn etc...
> How oracle determined which SCN is the recover start scn?and witch is
> finall scn?
> anybody know oracle recover iternal?? and who can exposed the  secret
> which in recvoer internal?
>  thanks !!

During normal operation Oracle records the highest SCN number written to the data file(s) in the control file and the data file header block. On startup Oracle compares the control file SCN to the data file SCN and responds accordingly.

The control file contains information of SCN numbers written to the archived redo logs. Oracle uses this to determine which archived redo log to start recovery with.

HTH -- Mark D Powell -- Received on Wed Nov 12 2008 - 10:16:42 CST

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