Re: Query takes too much time

Hello Ivan, Please help us to better understand your problem by giving some additional information: - what is the output of 'mserver5 --version'? - on which hardware + OS are you running monetdb? - what is the exact query you want to run on monetdb? what is the schema (you mentioned one table in your first e-mail) and how many tuples in each table? - what is the exact query you have run on mysql? - what is the execution time on mysql and monetdb? - Are there any other applications running at the same time, e.g., browser, mail client, chat program, music. Thanks! Best regards, Jennie On Dec 04, 2012, at 20:13, Ivan Videla wrote:

Hi Stefan,

That was an example of a query that takes too much time. Really i want to make a join from 3 tables. Each table has a column reference to another. For example tableA.col1 = tableB.col1 and tableB.col2 = tableC.col2 . My question is because each table has a foreign key that holds that reference to next table. Anyway is taken more time than the same query running in mysql. So, I think that I am doing something wrong.

Regards,

Ivan

El 04-12-2012, a las 16:06, Stefan Manegold escribió:

...

Hi,

a simple multiplication plus global sum will be executed byt two simple scans, one over the two base column to calculate the multiplication and one over the multiplication result to calculate the sum. There is not need for or benefit from any index. MonetDB will caluculate the result as fast as your machine (CPU speed, memory size and speed, disk speed) allows.

Stefan

On Tue, Dec 04, 2012 at 03:52:10PM -0300, Ivan Videla wrote:

...

Hi All,

I have a table with 268 millions of records from supermarket transactions tran_id, prod_id, quantity, price, cost and i want to make a calculation like sum(quantity*(price-cost)). But this query takes too much time. I want to know if i can improve the results using an index. Or monetdb itself use an index on-the-fly. If not i would like to know how can i make an index to improve the execution time.

Regards, Ivan _______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list

-- | Stefan.Manegold @ CWI.nl | DB Architectures (INS1) | | http://CWI.nl/~manegold/ | Science Park 123 (L321) | | Tel.: +31 (0)20 592-4212 | 1098 XG Amsterdam (NL) | _______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list

_______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list

_______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list