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From Serge Huber <shub...@jahia.com>
Subject Re: SQL2 vs. QOM
Date Thu, 11 Aug 2011 06:21:55 GMT

I did a little bit of work on the SQL 2 parsing and executing, and really the parsing time
is insignificant. The real time is spent executing the queries, so SQL 2 vs QOM is not really
a bit issue.

But it's much easier to build QOM programmatically, especially if you need to modify queries
dynamically. On the other side SQL-2 is really great to work with for everything else :)

cheers,
  Serge... 

On 10 août 2011, at 22:56, Alex Parvulescu wrote:

> Hi Stephen,
> 
> If you use SQL2 then you'll have to accept the penalty of parsing the query
> to a QueryObjectModel. But I'd say this is not the biggest problem you'll
> run into.
> Doesn't this fall into the premature optimization category? ;)
> 
> I think the better part of the work will go into optimizing the actual
> query.
> 
> You can profile the parsing code, for your own piece of mind [0], maybe it
> will give you some comfort. Look at #createQueryObjectModel(String query)
> 
> best,
> alex
> 
> [0]
> http://svn.apache.org/viewvc/jackrabbit/trunk/jackrabbit-jcr-commons/src/main/java/org/apache/jackrabbit/commons/query/sql2/Parser.java?view=markup
> 
> 
> On Wed, Aug 10, 2011 at 5:45 PM, Stephen Byrne <stephen@lincware.com> wrote:
> 
>> I have an application specific model in my Jackrabbit repository and have
>> to dynamically generate JCR queries from an application specific search
>> syntax. Am I better off performance-wise having my code build the QOM tree
>> than generating SQL2?
>> 
>> If I use SQL2 (or XPath), Jackrabbit takes that statement and generates a
>> QOM tree, right?
>> 
>> --
>> Stephen Byrne
>> LincWare, LLC
>> stephen@lincware.com
>> 


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