Re: Why is JDBC so slow? [Viruschecked]

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Hello Joseph,

the question rather is: why are you coding THAT inefficient?
What you are doing, is summing up all dead-time in your program together,
because you are:
- - querying the database without a cursor. Please try 7.4 driver with setFetchSize()
- - you call getColumnCount(), which needs to load ALL objects from the server and count them.
- - you are creating a HUGE array of objects, which is already done by the driver, btw.
- - after you've swallowed all these things one after another, you spit it out in a quite inefficient manner (at least
forsuch a huge amount of data). 

So:
- - do NOT use getColumnCount. psql doesn't use that, too.
- - use a buffered outputstream. That's a java issue, ok, but hey, this is a virtual machine. So try to omit ping-pong
withthe OS. 
- - spit out the values as you get them, directly. No intermediate array. An not that big ones (this one goes to
survivoror even old gen heap, so SLOW!). 
- - as hotspot compiles on the fly, try running the test several times, and see what the performance does. Normally,
theprogram get's faster after 5-10 runs, in  
case of -server after 10-20, but then... whow.

hope that helps...

Patric


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