performance with repeated sql query

[Hartmut.Luttermann]

Hi,

I have written a test program to measure the performance of the SAP DB. 

It repeats the following query

SELECT  p.id FROM P p, A a  WHERE p.is_def = false  AND a.role='test_role'
AND a.type=1  AND a.name='test'  AND p.id=a.id  AND p.state=3

on table P and A. Table P contains ca. 850000 entities. The result of the
query will contain ca. 10000 entities.

p.id is defined as varchar (255) and there is an index on p.is_def and on
p.state.

 

The surprise is that the query takes different times from loop to loop. It
changes between 9s and 30s.

 

The test program runs in the Jboss-ApplicationServer in a stateless session
bean which manages the DB connection. The DB runs on another machine, so it
will not be disturbed by JBoss.

 

Hartmut Luttermann        

 


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