Re: Question about resizing datafiles

From: Nuno Souto <>
Date: Tue, 08 Jan 2013 21:19:25 +1100
Message-ID: <>

Michael Schmitt wrote,on my timestamp of 8/01/2013 8:56 AM:

> Does resizing a datafile put any sort of lock on the underlying objects or
> logfiles that would prevent updates from committing? We had an occurrence
> today during a resize of a datafile where the number of sessions doubled
> until it hit the max limit for the database. Grid control is indicating that
> the sessions were waiting on 'log file sync'. This is an active
> dataguard instance (does not use ASM for datafiles), so I was thinking
> perhaps the active dataguard played a role. Otherwise perhaps the I/O
> throughput just went south on us during the resize. The resize was adding
> 5Gig to a 10Gig file. Once the file resize completed, everything kind of
> fell back to normal

My DG is a bit rusty but if I recall correctly, depending on how it is setup the database may be waiting for the standby instance(s) to also expand the file. Once at least one of the standby dbs has finished applying the relevant portion of the relevant redo log, then all proceeds normally. Again: this is only in maximum protection mode.
But like I said: I'm a bit rusty on this and there may be other reasons.

Nuno Souto
in sunny Sydney, Australia
Received on Tue Jan 08 2013 - 11:19:25 CET

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