Important Performance Query

Question

Hi,
I have just started using Toplink ORM 10.1.3.3.
When I log the finest level of logs, I see some entries which could be big performance issues when I put the app in production. Has some one else noticed the same thing, or am I doing something terribly wrong ?
[TopLink Fine]: *2008.08.24 08:35:47.231* --SELECT SEQ.NEXTVAL FROM DUAL
[TopLink Finest]: *2008.08.24 08:35:49.394* --sequencing preallocation for SEQ: objects: 50 , first: 4,602, last: 4,651
[TopLink Fine]: *2008.08.24 08:35:49.805* --SELECT SYSTIMESTAMP FROM DUAL
[TopLink Finest]: *2008.08.24 08:35:52.018* --Assign return row DatabaseRecord(     MY_TABLE.MODIFIED_DATE => 2008-08-25 06:05:50.404)
The above logs correspond to single record insert in my application. One is for sequence and another for timestamp for optimistic locking. Simple operation like this is taking 2 seconds(just on server !) to perform an action and this will be involved in every query (at least the TS because of optimistic locking). So I am little worried about the performance.
Has anyone faced similar issue ?
Regards,
Ani

Answer 1

Thanks for the reply.
As rightly mentioned by you, the time taken for pre-allocation is not that big bothering factor for me as it is divided between batch size.
I need to have an timestamp field in my tables for auditing purpose and I am trying to reuse the same for optimistic locking.
In non ORM world, typically the system time is obtained using db functions. But I guess that ORM tool has to make a call and get the current timestamp from DB, set it in object and then only it can persist the obj.
i.e. I was expecting that to insert an entity following sql is formed insert into mytable(col1,col2) values(123,_sysdate_) . But instead of having sysdate or something similar, the timestamp is taken from the DB first, set into object and then persisted.
The reason for this behavior could be that the timestamp should be set in the object copy without having to perform a read after save.
I have not tried to run any performance test on my usage. As mentioned earlier, we have just started development and I was trying to explore the optimal way to use toplink right from the beginning.
Regards,
Ani