Daniel John Debrunner wrote:
[EMAIL PROTECTED] wrote:
Note B: If you're running with autocommit OFF, you should definately not
use the same connection object in multiple simultaneous requests (either
use synchronization or create multiple connections).
This is true even with automcommit on. Multiple threads using the same
connection with ResultSets will mess with each other, as per the JDBC
sprc. An executeQuery by one thread will close any ResultSet any other
thread is processing.
Could you elaborate on this?
I created a small test program which Prepares two statements in separate
threads, but uses the same connection object. I execute statement A and
read a few rows from the resultset in thread 1, execute statement B and
read a few rows from it in thread 2, do a little interleaved reading,
then read the rest of the rows from both resultsets in their respective
threads. Got no exception, indicating that no result set was closed.
I ran this in autocommit mode in both embedded and client/server mode.
Code excerpt below, in case my explanation of the test program was unclear:
t1.prepareStatement();
t2.prepareStatement();
t1.executeQuery();
t1.showRow();
t1.showRow();
t1.showRow();
t2.executeQuery();
t2.showRow();
t2.showRow();
t2.showRow();
t1.showRow();
t2.showRow();
t1.showAll();
t2.showAll();
I have seen some differing behaviour with respect to this in
client/server and embedded mode before (that's why I made the test), but
I couldn't reproduce any issue now.
--
Oyvind Bakksjo
Sun Microsystems, Database Technology Group
Trondheim, Norway
http://weblogs.java.net/blog/bakksjo/
