Re: JDBC v. native drivers -- JAVA400-L

    I completely agree with Chris.  Most of the "JDBC is slow" stuff comes
from not using SQL, indexes and so on properly.

    If you do want to try using the native driver, which certainly can help
when everything is happening on the AS/400, see the information about the
"native" option for the "driver" property under "Other properties" on the
"IBM Toolbox for Java JDBC properties" page at:

http://publib.boulder.ibm.com/iseries/v5r2/ic2924/info/rzahh/javadoc/JDBCPro
perties.html

    There are probably other performance related areas as well.  You may
want to check the other properties and some AS/400 and Java performance
FAQs.


                                                         Joe Sam

Joe Sam Shirah -        http://www.conceptgo.com
conceptGO         -        Consulting/Development/Outsourcing
Java Filter Forum:       http://www.ibm.com/developerworks/java/
Just the JDBC FAQs: http://www.jguru.com/faq/JDBC
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Que Java400?             http://www.jguru.com/faq/Java400


----- Original Message -----
From: <chrisd@xxxxxxxxxxxxx>
To: "Java Programming on and around the iSeries / AS400"
<java400-l@xxxxxxxxxxxx>
Sent: Monday, June 16, 2003 12:04 PM
Subject: Re: JDBC v. native drivers


>
> >I've got a process that runs natively on the 400 (via QSH) that's a
> >bit slow.  Currently, it's using JDBC connectivity and I'd like to
> >make it run faster (it needs to process about 200K records).
> Without seeing your tables, I can't say for sure, but I'm wondering if you
> have checked the queries your are using to make sure they are as efficient
> as they can be.  We run a fairly intensive eBusiness application using the
> Toolkit driver, and most of the time our database performance problems are
> related to indices not being built when necessary.  You can use the
"Visual
> Explain" function inside of the "Run SQL Scripts" function of Operations
> Navigator to examine your queries.
> In Visual Explain, you can see all of the tables involved in your query.
> If you see any of the source tables say that it is using a "Table Scan" to
> lookup records, click on that icon.  In the data that comes up on the
right
> side of the window for that table scan, scroll down until you see a
section
> labeled "Index advised information".  If it advises that you create an
> index, then create on over the columns that it refers to.  Do this for any
> of the other table scans that the optimizer recommends indices for.
>
> Try your query again to see if it is any faster.
>
> If it isn't then you may be using a query that can't be optimized very
well
> (a subselect, or something like that).  That may require a rework of your
> query or some other strategy.
>
> >How difficult would it be to convert the JDBC to native?  I'm using
> >SQL extensively and not sure if the native drivers
> >can support SQL.
> The implementation differences between the native driver an toolbox driver
> might cause some re-factoring to have to occur.  It's not something you
> want to do unless you have to, though.
>
> ----------------------------------------------------------------------
> Chris DeLashmutt
> Senior R&D Analyst
> LeasePlan USA
> 1165 Sanctuary Pkwy., Alpharetta, GA  30004
> Phone: 678-202-8695
> Fax: 678-566-8551
> ----------------------------------------------------------------------
>