On Mon, 20 Jul 2009, Kevin Grittner wrote:
> Oh, well, if you load all the data into Java's heap and are accessing
> it through HashMap or similar, I guess a factor of 100 is about right.
No, that's not what I'm doing. Like I said, I have implemented the very
same algorithm as in Postgres, emulating index pages and all. A HashMap
would be unable to answer the query I am executing, but if it could it
would obviously be very much faster.
> I see the big difference as the fact that the Java implementation is
> dealing with everything already set up in RAM, versus needing to deal
> with a "disk image" format, even if it is cached.
The java program uses as near an on-disc format as Postgres does - just
held in memory instead of in OS cache.
Matthew
--
Okay, I'm weird! But I'm saving up to be eccentric.
