Recovering individual dbspaces

Informix Ver 9.40.FC4 HP-UX 11.11 We have a 350Gb database running baan. The customer has added a number of new baan companies placed in new dbspaces for testing purposes. My question is if a corruption occured within one of the new companies would it be possible to restore the individual dbspace which contained the affected company, without affecting user access or the live data within the instance. I understand the "onbar -r dbspace1 dbspace2" is available but what about the logical logs? Would we not need to backup the individual dbspace before work commenced or is Informix able to restore one dbspace to a point in time without affecting all other data? Thanks in advance.... Howard

Hi, you can restore individual dbspaces while the system is running. This is possible only with so called non-critical dbspaces, it is called "warm restore" and requires restore of logical logs (which in turn requires that they were backed up before). However, you cannot restore individual dbspaces to arbitrary points in time (PITs). When doing a warm restore, you have to restore the dbspace to the current time, so that it will be consistent with the remaining dbspaces (that do not need to be restored). This is done by restoring logical logs and applying those log records that are involved with the restore dbspace. (Since the system is still running and logs are in use, the restored logs will need space in a temporary dbspace for this purpose). So, from your e-mail it is not quite clear what kind of "corruption" has occurred. If there was a physical corruption (e.g. on the disk), then IDS noticed this at the time and marked down the chunk (and dbspace) without further accessing it. Therefore a warm restore of the dbspace will restore everything that was done before the corruption occured. As there was nothing done afterwards, this will then be sufficient to get current with the rest of the system and all is fine. This is the situation warm restore is intended for. If you have a logical corruption (e.g. table or database dropped accidently), then IDS will have considered this normal work and will have continued doing work on the dbspace. IDS did not mark down the dbspace without further accessing it. Therefore a warm restore would have to roll forward all this "work", including the "corrupting action" (table/dbspace drop, ...). I understand that in this situation you would want to say "I don't care about system consistency (among restored and not-restored dbspaces)", but this is (so far) not supported. What you can do in such a case is to restore to a different (temporary) IDS instance just the critical dbspaces and the dbspace with your corrupted database. You do not need to restore any of the other, non-critical dbspaces. Since this will be a cold restore you can do this as a PIT restore to the desired point in time (before the corruption occurred). Then you can access, export, whatever, the database and its data ... (With IDS 10.00 an alternative would be Table Level Restore.) Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management IBM Deutschland GmbH Chairman of the Supervisory Board: Hans Ulrich Märki Board of Management: Martin Jetter (Chairman), Rudolf Bauer, Christian Diedrich, Christoph Grandpierre, Matthias Hartmann, Thomas Fell, Michael Diemer Corporate Seat: Stuttgart, Germany; Reg.-Gericht: Amtsgericht Stuttgart, HRB-Nr.: 14 562 WEEE-Reg.-Nr. DE 99369940 "howie.lfc@googlemail.com" <howie.lfc@googlemail.com> Sent by: informix-list-bounces@iiug.org 19.07.2007 08:48 To informix-list@iiug.org cc Subject Recovering individual dbspaces Informix Ver 9.40.FC4 HP-UX 11.11 We have a 350Gb database running baan. The customer has added a number of new baan companies placed in new dbspaces for testing purposes. My question is if a corruption occured within one of the new companies would it be possible to restore the individual dbspace which contained the affected company, without affecting user access or the live data within the instance. I understand the "onbar -r dbspace1 dbspace2" is available but what about the logical logs? Would we not need to backup the individual dbspace before work commenced or is Informix able to restore one dbspace to a point in time without affecting all other data? Thanks in advance.... Howard _______________________________________________ Informix-list mailing list Informix-list@iiug.org http://www.iiug.org/mailman/listinfo/informix-list