[Mondrian] Multi-threading SQL execution

Julian Hyde julianhyde at speakeasy.net
Tue Feb 13 21:17:10 EST 2007

> > I want to challenge Michael's assertion that "almost no 
> JDBC driver will 
> > allow parallel queries". It may be true, but if so, it will 
> cost us a 
> > lot of effort to do things another way, so I want to see 
> some evidence. 
> > Michael, can you give an example of a JDBC driver which 
> cannot execute 
> > two statements in the same connection (and transaction context)?
> http://www.mysql.com/news-and-events/newsletter/2003-04/a0000000154.html

Thanks John. That's good enough evidence.

Let me also challenge the assumption that in the typical mondrian
installation, the contents of the DBMS are dynamically changing. My
impression is that in 95% of cases, data is loaded nightly or weekly. There
are clearly exceptions - as Michael and Bart have both explained - but we
should not treat the exceptions as the norm.

Option #2 (parallel query execution) is viable and valuable to the majority
of the mondrian community, and we shouldn't be too hasty in ruling it out.
Option #1 (ROLLUP) has limitations in its applicability too, because not all
databases support that syntax.


More information about the Mondrian mailing list