Re: Is it thread-safe to pool the PreparedStatement?

I don't think PreparedStatements can be used by multiple threads
concurrently since you could have thread A calling setString(1, "a") and
thread B calling setString(1, "b") on the same prepared statement and
the result won't be what you expected. Or in other words, regardless of
them being thread safe or not, you (your app) probably don't want to use
them concurrently anyway.

It's worth pooling them, specially if the app makes lots of db
operations, and in fact jdbc 3.0 already does that. See
http://www.javaperformancetuning.com/tips/jdbc_prepared.shtml for
details.

In your case you can make sure only 1 thread can use a particular
prepared statement when the thread tries to retrieve it from the map. If
the map is the only place you can retrieve preparedstatements and access
to the map is properly synchronized, then you don't have to check any
uses of preparedstatement on the rest of the code.

You can still reuse preparedstatements later, just not at the same time
by multiple threads, unless you want to have some kind of random
behaviour.

Hth,

Horaci

-----Original Message-----
From: Discussion of advanced Java topics.
[mailto:[email protected]] On Behalf Of Carfield Yim
Sent: 20 August 2007 12:47
To: [email protected]
Subject: [ADVANCED-JAVA] Is it thread-safe to pool the
PreparedStatement?

I just join a project, this existing team member of this project
concern performance a lot so their pool all PreparedStatements into a
map (probably not a nice optimization, but I have no say about that)
when the application start. And then reuse those preparedstatement
again and again.

I haven't get time to check all method call using those
preparedstatement are synchronized properly. If that is not the case,
is it thread-safe to pool the PreparedStatement?

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