Re: Suggestions for improving performance?

[Barnet Wagman]

A couple questions/issues: Re logging: Something I read in the Derby documentation (or perhaps in the mailing list archive) indicated that logging may be expensive. Is there any way to disable logging completely? I think there is no option available in derby to disable logging . Might be good option for Derby to provide in future releases. Any idea of difficult this might?  I've been thinking about poking around in the src to try to do this. Re record vs table locking: "Tuning Derby" indicates that record level locking can add a lot of overhead and implied that there's a way to force table locking, but it wasn't clear to me how to do this. 1) you can acquire a table level lock using LOCK TABLE sql statement . ex: lock table t1 in exclusive mode 2) There is also lock escalation mechanism in derby. When locks on particular table in a transaction reaches a threshold values(default:5000). it automatically escalates the row level locks to a table level lock. Lock escalation threshold value can be changed by setting derby.locks.escalationThreshold property. I would not recommend reducing the threshold if the tables are being accessed concurrently. Am I correct in my understanding that escalating to table locking speeds things up?  If so, any idea what threshold level might help?  Also, does this locking mechanism come into play with reads, or just with writes. Thanks