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From: "Jan Burse" <jan.burse@THRWHITE.remove-dii-this>
Subject: Re: jTDS, trashes heap wi
Message-ID: <4829DD03.6010102@fastmail.fm>
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Date: Wed, 27 Apr 2011 15:21:45 GMT
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  To: Lew
Lew schrieb:
> You make it sound so dire.  Allocating these objects takes next to no 
> time, GC will be fast since they'll all be unreachable, and you don't 
> have to worry about it.  Not only that, but Hotspot will probably 
> optimize away the object calls in favor of primitives anyway, possibly 
> enregistered.

The hotspot is not infinitely smart, and alloc/gc is not negliable.
Try the following two codes:

Variant 1:

    Color red=new Color(0xff0000);
    g.setColor(red);
    for (int x=0; x<1000; x++) {
      for (int y=0; y<1000; y++) {
         g.drawRect(x,y,1,1);
      }
    }

Variant 2:

    for (int x=0; x<1000; x++) {
      for (int y=0; y<1000; y++) {
	Color red=new Color(0xff0000);
         g.setColor(red);
         g.drawRect(x,y,1,1);
      }
    }

There is a huge difference between the two
in performance.

Similarly one can waste performance in JDBC
drivers or what ever...

Best Regards

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