Re: [MonetDB-users] Why does MonetDB take indexes not into account?

On Wed, Nov 28, 2007 at 09:23:01AM +0100, Markus Gritsch wrote:

On 28/11/2007, Niels Nes wrote:

...

The optimizer nicely finds out that you have an foreign key. This foreign key comes with a join index. Unfortunately when having these indices we do the selects on the base columns, ie on the columns of entry and act independend of the join. And only after that we use the index to combine these results. The improved optimizer will first do the select on the primary key 'column', use the join-index, then the select on this reduced column.

Great. Lets hope this change does not degrade preformance in other cases. Do you have any test suit, which runs various queries,

Yes: http://monetdb.cwi.nl/projects/monetdb/Development/TestWeb/index.html http://monetdb.cwi.nl/projects/monetdb/Development/TestWeb/Stable/index.html http://monetdb.cwi.nl/testing/projects/monetdb/Stable/sql5/.mTests103/index_...

measures their performance,

Kind-of: http://monetdb.cwi.nl/testing/projects/monetdb/Stable/sql5/.mTests103/times....

and indicate if performance decreased?

unfortunately not yet. For now, our (nightly automatic) testing effort are mainly focused on ensuring and monitoring functinal correctness and portability. Performance monitoring beyond measuring and archiving the execution times of the functionallity tests is on our wish-list, but so far, each day ended after just 24 hours ... ;-) Stefan

Markus

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