AW: statement too big for the log device

> -----Ursprüngliche Nachricht-----
> Von: Martin Lackner [mailto:martin.lackner@xxxxxx] 
> Gesendet: Donnerstag, 17. März 2005 19:38
> An: maxdb
> Betreff: statement too big for the log device
> 
> 
> Hello,
> 
> I've run a single update-statement with dbmcli on a table 
> with a lot of 
> rows, were most of them were changed. The log device is too 
> small and so 
> it ends up in log full. I'm not able to do anything with the database 
> then (like change the state of the db). autolog is on, but 
> that does not 
> matter her, because it can't backup data in the log-device 
> with is maybe 
> rollbacked (as far as I know). I always thought maxdb use 
> space in the 
> data-device if a single transaction is too big for the log device??

Thats true only for releases prior to 7.4. In the newer releases
undo-information is always written into the datavolumes. Redoinformation
is written to the logvolume.

> 
> If I run the same sql-statement in the loadercli, several
> (auto-)log-backups are made. It seems, that the loadercli devides the 
> statement in several transactions.
> 
> I had a backup, so I killed every thread belonging to this 
> DB, and then 
> I were able to drop and recreate it.

Did you try to restart the database after killing? This should always
be possible.

> 
> How can I "recover" in this LOG FULL situation and bring the 
> DB back to 
> live when I have not a backup for the state just before? I have this 
> behavior in 7.4.23 and 7.5.19.

Normally a logbackup should solve the situation. Pages on the logvolume
may be reused if two conditions are fullfilled:
1) they must be already saved
2) they are not needed for the next restart (e.g. the last savepoint is
   younger than the pages which will be reused)

Could you please have a look into the file knldiag, whether the last savepoint
hase been completed? you should find a message like
2005-03-04 10:57:41      0x94C     53071 SAVPOINT B20SVP_COMPLETED: 31

Kind regards, Martin

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