AW: Dumb DBA mistakes

david@smooth1.co.uk wrote: > Dumb mistakes. > > - some idio^H^H^person I once trained had LTXHWM and LTXEHWM set too > high > and filled their logs. 30 and 40 should be made manadatory. You can > have 32767 logical > logs - use more logs. And make them all the same size. > I disagree. LTXHWM and LTXEHWM should be set, so that any transaction that might be executed by you application does not lead ot the case where the rollback cannot complete as all logs are 100% full. This can be very much higher than 30 / 40 depending on you application. 30 / 40 is probably a waste of resources for most systems. SAP R/3 has 70/80 by default and in all the years supporting SAP R/3 I had once a case wher the logs filled up and rollback was not able to complete. This was an extrem case on a test system: - Only one transaction was active all the time , so it did not only süpawn but also actually use all of the 70% log space. - it did only updates this means that it produced very small forward log entries compared to the size of the compensation log record. This resulted in a situation where the rollback needed more space than was available. Under normal OLTP conditions (many users , short transactions) 70/80 is sufficient most of the time , I guesss, and makes good use of your log resources. This might be different for DSS environments where you have few concurrent users with large transactions. Apart from that in IDS 9.4 and higher there is a new feature - DYNAMIC_LOGS - which allows the creation of logical logs on the fly in such a bad case. Regards Tilman