OCI ofen array fetch performance

We are using ofen to array-fetch thousands of rows of data across the network. A typical query is something like "select column_1, column_2, ..., column_N from MyTable". We have experimented with array sizes between 500 and 5000 and notice three things:

1. There is no noticable performance gains for very large block sizes.
2. For a table with, say, 20000 records, the first fetch of 500 takes around 20 seconds, with each successive fetch taking much less time, maybe a second or less.
3. For some tables, executing a simple query for a single row before the first ofen call will dramatically reduce the time spent in the first ofen block fetch, but for others it will not.

Can someone explain this? How can we cut the time spent in that first ofen call?

eabaggot_at_hiwaay.net Received on Wed Feb 04 1998 - 00:00:00 CST