Re: MonetDB performance disappointing

Well ok, the values for the between statement were wrong. It should be between 189 and 368 :) The result is now right, but the execution time stays the same or is even minimal longer than before. I have uploaded a trace to my dropbox of the query. https://www.dropbox.com/s/q2j9g0gsvaylkw6/query_trace_.txt?dl=0 https://www.dropbox.com/s/q2j9g0gsvaylkw6/query_trace_.txt?dl=0 Regards, Martin

Am 26.06.2015 um 13:45 schrieb Martin Schwitalla :

Hi,

the prefilter makes it faster, but somehow i get three times more tupels in the result than before. How is that possible?

((calls.sample_id BETWEEN 226 AND 369) AND calls.sample_id IN (227, 230, 233, 234, 237, 190, 195, 198, 199, 203, 270, 273, 276, 189, 343, 366, 367, 368))) AS anon_2

Best regards, Martin

...

Am 25.06.2015 um 22:08 schrieb Martin Kersten :

Hi

On 25/06/15 17:38, Martin Schwitalla wrote: ...

...

...

...

I added some primary and foreign key constraints and set the database to readonly, but it didn`t do much. The trace tells me that some joins take the most time and some subselects also take much time. But nothing besides that. The query has 10 joins.

... Indeed a complex, probably generated SQL query. The trace information of the expensive joins and thetaselects would be my first target.

An expensive join might typically result if its hash support does not fit in memory, which will cause disk accesses. The predicate (calls.sample_id IN (227, 230, 233,.... and the like probably produce to multiple thetaselect that are merged in the end. It might help (worth trying) to put a range pre-filter (call.sample between 227 and 368 and calls.sample in (227,....))

The fact that minimal-pipe is better then the default-pipe indicates a lot of competition for scarce resources during execution.

regards, Martin _______________________________________________ users-list mailing list users-list@monetdb.org https://www.monetdb.org/mailman/listinfo/users-list

_______________________________________________ users-list mailing list users-list@monetdb.org https://www.monetdb.org/mailman/listinfo/users-list