Re: Increase the size of rollback segments

Why avoid dropping them? There's no point. Create a new one first, then drop the old ones. Incidentally, Optimal is a very bad idea (it will cause shrinking just exactly when you don't want it to happen: when a new transaction is looking to acquire new rollback blocks).

I suppose that a specific answer to your actual requirements might be: alter rollback segment to have optimal of a bezillion megs, and let it expand as necessary during normal operations. Since it will never hit optimal, it will retain all the extra extents it acquires as part of normal operation.

Oh, 20 extents is duff as well... totally unnecessary these days. The recommendation for 20 comes from the old Oracle 6 days when transactions couldn't share extents. Half a dozen appropriately sized extents is fine for Oracle 7.1 onwards.

Regards
HJR

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<aschex_at_my-deja.com> wrote in message news:8s7hrm$vho$1_at_nnrp1.deja.com...


> I've created several rollback segments with the following options:

> initial 512k next 512k minextents 20 maxextents 200 optimal 50m

>

> The problem I'm running into is I'm getting snapshot too old error. I've

> checked the size of my rollback segments and they are each about 10-20

> megs in size. What I would like to do is increase the size of each

> rollback segment to about 50 megs in size. Is there an easy way of

> allocating additional extents to a rollback segment? I was hoping to

> avoid dropping and recreating the rollback segs.

>

> Thanks for your help,

> Andy

>

>

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