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From Brett Wooldridge <brett.wooldri...@gmail.com>
Subject Re: Performance degradation with Derby Embedded under Tomcat vs Jetty
Date Tue, 14 Apr 2015 07:03:15 GMT
While it may be that PostgreSQL is faster, make sure you are measuring accurately.

First, you should be running the Java Server VM, preferably Java 8.

Second, the server VM JIT compile threshold is 10,000 executions of a given method -- so the
VM will get faster and faster as it progressively compiles code.  I would run 10000 queries
though Derby before taking measurements.

Lastly, PostgreSQL may be running with substantially larger page caches by default.  To the
point where much of the data may be completely in memory.

  Read the Derby Tuning Guide to set the page cache to as close to the same size as PostgreSQL
as possible.

Sent from my iPhone

> On Apr 14, 2015, at 15:30, √ėyvind Harboe <oyvind.harboe@zylin.com> wrote:
> I compared the performance on PostgreSQL vs. Derby for this report. Unsurprisingly PostgreSQL
performs much better.

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