Profiling example program of hsqldb java

Question

Basically I am trying to profile web application which runs on tomcat and uses hsqldb(insecure web application from OWASP). I am using java profiler(jp2-2.1 not widely used at all)to profile tomcat server. The profiler profiles sequence of method call in which they executed in xml format. In short it generates calling context tree of the program/application run.

I noticed that the sequence in which methods of hsqldb get executed differ for EXACTLY two same runs of an application. which I expect to be same. To confirm this, I tried to profile sample program of hsqldb and profiler again generated diffrent output for the same program.

I am running the sample program from here: (http://hsqldb.sourceforge.net/doc/guide/apb.html)

So now I am sure that, the sequence in which hsqldb methods get executed, differ for exact two same runs of the program.

Could someone please tell me what is the reason behind this ? I would be very curious to know this.

I have not used hsqldb ever so dont know in detail how it works exactly.

Thanks.

Answer 1

The sequence in which HSQLDB methods are executed should generally be the same if the executed SQL statements are exactly the same, and each run starts with an empty database.

There will be minor differences between the first run and the runs that follow, because some static data is initialised in the first run.