Re: SAPDB performance, HELP PLEASE!!!!!

Hi Jose,

If those are some kind of select statements then it
would be goot to try to isolate a problem. For example
try running those queries not from tomcat, but from
sqlcli both sequential and parallel, it would leave
JDBC driver and tomcat out of the equation.

When I was evaluating MaxDB I tested performance for
parallel queries and didn't notice any problems.
Parallel queries on single CPU server were executed
(time between start of the first query and finish of
last one) not slower than same ones sequentially.

Alexei.

 --- José Rómulo Elías Contreras
<romulo@xxxxxxxxxxxxxxxxxxxx> wrote: 
> Hello:
> 
> I am very worried because people have not been able
> to help me with my 
> problem:
> 
> I test the performance of SAPDB in two tomcat
> servers connecting to the 
> same database. Each tomcat server open 10 
> sessions with the next parameters:
> 
> DriverManager.getConnection(databaseUrl +
> databaseName + "?user=" + 
> databaseUser + "&password=" + databasePassword +
> "&timeout=0&isolation=" 
> + java.sql.Connection.TRANSACTION_READ_UNCOMMITTED);
> 
>   I open 4 differents browser sessions connected 2
> to each tomcat 
> server. If I request the same information in each
> different browser 
> session at the same time the performance go down.
> The first session 
> connected to tomcatServer1 takes 9 seconds to
> execute the query, the 
> second session connected to tomcatServer1 takes 12
> seconds to execute 
> the query, the third session connected to
> tomcatServer2 takes 14 seconds 
> to execute the query and the fourth session
> connected to tomcatServer2 
> takes 16 seconds to execute the query aproximately.
> If I open only one 
> browser session to execute the query, then the query
> takes only 3 seconds.
> 
>   I measured the time before calling the execute
> method of the 
> statement, and afterwards:
> 
>   // Before execute statement save time (time1)
>   ResultSet rs = statement.executeQuery( sql );
>   // After execute statement save time (time2)
>   // differenceTime = time2 - time1
> 
> Why does the performance go down?
> How can I correct it?
> 
> 
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