Re: Oracle vs MySql Performance

On 21 Aug, 13:46, "Shakespeare" <what..._at_xs4all.nl> wrote:
> "sybrandb" <sybra..._at_gmail.com> schreef in berichtnews:1187699217.556380.259900_at_19g2000hsx.googlegroups.com...
>
>
>
>
>
> > On Aug 21, 1:58 pm, Johne_uk <edg..._at_tiscali.co.uk> wrote:
> >> Hi,
>
> >> I'm looking for a few opinions on an issue we are experiencing.
>
> >> My company currently uses a 3rd party application. Up until a few
> >> weeks ago this application consisted of Java code and a database layer
> >> that used MySql.
>
> >> Performance on MySql was adequate but as our primary DB platform is
> >> Oracle we influenced the 3rd part to introduce an Oracle version (NB:
> >> most of the sql code is stored in a java db layer - schema just
> >> consists of tables, views and indexes).
>
> >> To facilitate this process the vendor has used almost pure ANSI Sql so
> >> that the same sql can be used for both oracle / mysql with minimum
> >> conversion required.
>
> >> When the system was released we were surprised to find that the sql
> >> (and hence application) ran slower on oracle than MySql (the Oracle db
> >> server is also considerably more powerful).
>
> >> At a high level does this surprise anybody on this forum. Does Oracle
> >> struggle to execute ANSI sql compared to MySql.
>
> >> The orginal code was also written for MySql and converted so that
> >> might explain why is is running slower.
>
> >> Any thoughts would be appreciated.
>
> >> Tanks in advance
> >> John
>
> > Oracle compared to MySQL <--> Apples to Pears.
>
> > The architecture is completely different.
>
> > 'Porting' Sqlserver, or MySQL to Oracle NEVER works!!!!
> > If you read any book by Tom Kyte, you will know why.
> > Set up a database agnostic app and you will notice you don't use the
> > power of a database anymore, and you will primarily use it as an
> > expensive replacement of a system running on punch cards.
>
> > --
> > Sybrand Bakker
> > Senior Oracle DBA
>
> Still one could expect the system to run at least as fast as the punch
> cards...
>
> Advise: have an Oracle DBA to look at the server and the SQL to analyze this
> problem. For example: did you run statistics on the Oracle DB? It might even
> be a problem in the communication between the (java) application layer and
> the database. Did you take a closer look at the indexes? Some of them might
> not be optimal for Oracle. Are all foreign key relations well-defined,
> indexed etc? What version of the Oracle DB are you using anyway?
>
> Porting an application from MySql to Oracle is never optimal, but the port
> could be a starting point to rebuild (parts of) your application, eg by
> porting code (takes reprogramming) from your application to the database.
>
> Shakespeare- Hide quoted text -
>
> - Show quoted text -

Thanks for the prompt replies guys, guess you are really telling what what i already know.

The phyiscal db structure (indexes etc.) was coverted as is from Mysql. The bulk of initial performance problems were removed by gathering stats on oracle.

I guess we need to look at the issues from two plans of attack. First, look at optimisations for the oracle schema and second, take a look at the java layer and its interaction with Oracle.

rgds Received on Tue Aug 21 2007 - 09:30:14 CDT