I am working on a performance critical application .I need to retrive Ids of thousands of employees and store them in String and some times in int .
On testing my application using JProfiler I found that much of the processing time is being spend iterating over resultset.
I am using the following kind of code
List empList=new ArrayList();
I found that getArray() method of resultset is useful but I am not finding a suitable driver for this.Also my application needs to support multiple databases like SQLServer ,Oracle and Postgresql
Can any one help me in this .
Having just dealt with this issue - your problem is more likely with your cursor type. You might want to change the fetch size. Oracle drivers default to 10. I found that 500 to 1000 is better. At least for the situation I was in.
If your application needs to support multiple dbs - check out Hibernate (http://hibernate.org/ ) or a JDO vendor. I like Hibernate.
I am not getting performance even after uisng fetch size.
Can u sugget me drivers that support the getArray() method of resultset for SQLServer and Oracle
I don't know of any that do. Mostly becuase I have not researched it because it was not needed.
I doubt the slow down is in the resultset.get___ . I've used Oracle to return large numbers of objects. The slowness was in pulling the data. Not building the objects.
Yes u are absolutely right.
setFetchSize actually improved the performance my problem was mainly in retrieving data which was solved by optimizing the query
Thanks for suggestion
Excellent. Good call on the query too.
Remember that the driver and cursor type and network all can affect how it performs.
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