Re: rollback question

Chuck Hamilton wrote:
>
> Someone recently told me that all rollback extents for a transaction must
> be contiguous. If a transaction attempts to allocate the next RBS extent,
> and that extent was already assigned to another transaction, that the first
> transaction will fail with a "snapshot too old" error. It will not skip
> over that extent and grab the next one. Is this true?
> --
> Chuck Hamilton
> Xchuckh_at_dvol.com
>
> In an effort to reduce spam, my return address has been altered.
> To reply, remove the X from the address.

No, the rollback segment will allocate another extent in this case. It does
not skip extents. Snap shot too old occurs if the rollback segment overwrites
committed changes needed for reconstructing read consistent image for a long
running query.

-- 
Regards,

Virag

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Virag Saksena                XvsaksenaP_at_us.oracle.com Remove the X and
the P
Senior Principal Consultant                                    
650.506.5087
System Performance Group
Oracle Services
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