ResultSet.absolute(int) Performance Issue

Question

I'm using the Oracle driver. I've run some tests and it appears that:
ResultSet rs = ...;
rs.absolute(n);
has approximately the same performance as:
ResultSet rs = ...;
for (int i = 0; i < n; i++)
rs.next();
Is this all it is doing? For large values of "n" this could be very bad.
I'd use "ROWNUM", but I also use an O/R framework. The only way to
pull out specific subsets is to use JDBC scrolling. Is there anything I
can do?
Thanks,
Bob

Answer 1

Bob Lee wrote:
There are at least 4 oracle driver vendors and
multiple versions from each, so let us know
which one you're using. See more below...I've tried the Oracle OCI (thick) and thin drivers, version 9.
It certainly may be doing this. Very few drivers would go to the
DBMS for each row individually, in a random access fashion.
The driver would probably obtain and buffer all the intermediate
rows that had not been fetched.This sucks. If I call ResultSet.absolute(), I probably don't need all of
the intermediate rows.But you asked for them, so the driver and DBMS think you probably
want them. Absolute() is part of implementing random access. It would
never be interpreted as 'I don't want (some) rows'. It can be called to
go backwards from the current position too.
Clever SQL can be made to select the subsets (contiguous ranges) you want, one by oneDamn.It's a solution.... This sounds like something you want to do in a stored procedure.
The cardinal performance problem in RDBMS applications is shipping scads of
raw data out of the DBMS to the client, to be processed and/or discarded, instead
of processing the raw stuff where it is in the DBMS.
Good luck,
Joe
>
Thanks,
Bob
Thanks,
Bob