autocommit is a good idea, but I have slow connect with remote server
and need to select this items at max speed

Manual commits in a loop with also slow things down.

Another frequent Java coding mistake is to build the SQL string manually
by concat'ing the literals into the string.  A knowledgeable ORacle
Java developer will use bind (aka positional) parameters when appropriate.
Under many circumstances building a SQL stateement as a string and
executing that string dynamically is a wonderful way to kill ORacle
performance.

Another thing to look at is bulk binding & array fetching..

All these techniques are well described in the online Oracle Java
Developers and JDBC Developers manuals.  Which most Java developers don't
read :-(

A commit would require waiting for a write to disc to complete. How slow
that is depends upon what you are logging to. Solid state memory will be
significantly faster than rotating media. When you switch auto commit
off (which should be a matter of course) make sure to commit (or
rollback) when you've finished.

If your driver supports it, then bulk updates should be very much faster
with a networked driver. If they don't perhaps you could generate an SQL
statement which takes a number of rows at once. Or perhaps moving the
code writing to the database onto the same physical machine. If you're
really, really, really desperate, write stored procedure to decode a
long argument and insert multiple rows.

Tom Hawtin

Generally agree if using the same rdbms.  But export from Oracle, import
to MySQL?