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RE: [MaxDB] in case of crash + Strings comparison

From: Zabach, Elke (elke.zabachsap.com)
Date: Mon Jan 19 2004 - 07:34:19 CST

Lenaig.Moulinensiacet.fr wrote:

> Hi,
>
> I have a few questions about MaxDB.
>
> 1/ In case of crash in MaxDB, what can we do ?

Usually a normal restart (db_online) will do.
After this it is assured that all transactions committed before the crash
are done in the current state of the db, all transactions rollbacked before the
crash will not exist in the current state of the db and all transactions open
(neither committed nor rollbacked explicitly by the user) at the time of the crash
are handled like rollbacked transactions.
--> the result is the same as with every database system having transaction-consistency.

> In Oracle, the function Rollback Segment allows to come back to the
> previous state of the database, in case of failure, but
> Rollback Segment
> doesn't exist in MaxDB.
> So, is it possible to come back to a state that is not too
> far from the
> one we were at the moment of the crash ?

The restart-behaviour of databases has nothing to do with the existance
or not-existance or the explicit or implicit creation and size-definition for them.
--> with MaxDB you will reach the last consistent state (all transactions closed,
nothing half-way done/undone) as with Oracle.

>
> 2/ The functions TO_CHAR, TO_DATE, TO_NUMBER exist in MaxDB,
> but I read in
> the documentation that the "non padded comparison" (as called
> in Oracle)
> wasn't possible.
> Is it possible to do a "normal" Strings comparison ?

What do you mean with 'normal' string comparison:
column = 'xyz' resp. column <> column or the like?
YES, of course

But what has this to do with the functions TO_DATE, TO_NUMBER ?

Elke
SAP Labs Berlin

>
> Thanks,
> Léna
>
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