RE: Need suggestion on Hibernate+Oracle

Hi Zhai

>The developers of our new project chose JBoss+Hibernate as middle tier,
>and the backend maybe take single instance or RAC of Oracle 10g.I think
>hibernate is a good choise for developers,but maybe not for DBA.

Mhmm... the developers use the persistence framework, therefore it's a = good idea that it's a good choice for them!

>I want to know what will be the impaction to oracle if using Hibernate=20
>or Toplink kind of tools,from the standpoint of Oracle DBA? And what=20
>should I consider during physical design and maintenance phase?

The goal of a transparent persistence framework like Hibernate is that = the developer should design the object model independently from the = database design. This makes sense since the two models are completely = different! Then a mapping between the two is done through a = configuration file. Of course we don't work in an idea world... = therefore a marginal impact is to be expected.

>Some SQL tuning chances will be lost as most SQLs will be created by=20
>these tools,right?

Simple statements, which usually are the great majority, should not need = tuning.=20

For complex statements (e.g. a report containing analytic functions) it = makes no sense to go through the persistence framework. Hibernate let = you use plain JDBC to handle such situations.

>Tom said the Hibernate "scared" him,because "transaction handling =
outside
>the database" and "abstract the database to a bit bucket", what do you =
think?

Tom is scared from everything that doesn't run in the database ;-)

In Hibernate transaction handling is "configurable". The application can = use plain JDBC transactions (i.e. use the transaction handling of the = database...) or, when more complex (e.g. distributed) transactions are = needed, use API like JTA.

>And what do you think about "midder tier java object cache"?Is it =
really reliable?

Personally I don't care if they are reliable or not... in fact they are = often not needed!

HTH
Chris

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