Re: JDBC Overhead

Bob,

On other systems try putting the start time before the prepareStatement

Depending on the system they will parse the statement in the prepare,
we defer server side parsing until the execute.

Also what is the overhead of a second executeQuery ?

Dave
On 1-Aug-06, at 4:05 PM, Bob Damato wrote:

> It appears to me as if there is quite a bit of overhead with the
> Postgres JDBC driver when compared with other JDBC drivers. This
> simple piece of code shows me something very odd:
>
> -------------------------------------------------------
> ps = con.prepareStatement("SELECT 1");
> long execStart = System.currentTimeMillis();
> rs = ps.executeQuery();
> System.err.println ("Query executed in " + (System.currentTimeMillis
> () - execStart) + "ms");
> --------------------------------------------------------
>
> Result of this code is:
> Query executed in 57ms
>
> But with duration logging enabled on the database side, I can see
> that the database side processing time was less than 1 ms.
>
> LOG: duration: 0.073 ms statement: EXECUTE <unnamed> [PREPARE:
> SELECT 1]
>
> When I run this same code against a mySQL or Sybase database, I get
> 1ms execution time. Am I missing some bit of tuning that I can do
> with the database or the JDBC driver to eliminate that 50+ms of
> latency?
>
> I am running postgres 8.1.4 on solaris and I've tried all 3 JDBC
> drivers. The java program is running on the same server as the
> database so I don't believe there is any network latency involved.
>
> Thanks!!
>
>
> ______________________________________________________________________
> _______________
> Bob
> Damato
> Cox Target Media
> Internet Technology
> Manager
> Largo, Florida
>
> Our greatest glory is not in never falling, but in rising every
> time we fall. -- Confucius
>