Bruce,
I think a union join on the dependent tables would give us better
performance.
<table expression 1>
FULL OUTER JOIN
<table expression 2>
ON 1 = 2;
I think it would be sum of all the dependent tables.
The cost of the left outer joins is the cartesian product of all the
dependend tables.
Steve
----- Original Message -----
From: "Bruce Snyder" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, July 09, 2004 7:45 AM
Subject: Re: [castor-dev] JDO object creation performance flaw
>
> Werner Guttmann wrote:
>
> ..
>
> >> - Most of the OQL is gone from the system now; our use of caching has
> >>made it pretty much a prerequisite that we cache id lists for SQL
> >>queries on finders and only use db.load() on calls. While I'd love
> >>that to change, the OQL engine just wasn't far enough along to be able
> >>to represent our queries.
> >
> > Afaik, Bruce is still thinking about replacing the whole OQL engine with
a more advanced solution. But I have to leave it up to him to present his
own
> > thoughts on thi subject.
>
> This is something that will be provided by a project out on CodeHaus
> named Tranql. My friends Jeremy Boynes and David Jencks are committers
> on this project but we're all so busy at the moment that we haven't
> worked on it in a couple of months, but it's still needed for Geronimo
> and I see a definite need for this in Castor, so we'll definitely get
> back to it.
>
> Anyway, the idea is to accept a string query or a programmtic query and
> transform that into the necessary query to suit the data source on the
> back end, no matter whether that data source is a relational database
> (SQL), a native XML database (XQuery), an EJB container (EJBQL), etc.
> The idea is that transforming into any query language will be easy to do
> via Tranql.
>
> Hopefully after I get the initial cut of the Castor Live book out I'll
> have some time to work on this (and other things, too!).
>
> Bruce
> --
> perl -e 'print
> unpack("u30","<0G)[EMAIL PROTECTED]&5R\\"F9E<G)E=\\$\\!F<FEI+F-O;0\\`\\`");'
>
> The Castor Project
> http://www.castor.org/
>
> Apache Geronimo
> http://incubator.apache.org/projects/geronimo.html
>
>
>
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