[MonetDB-users] Profiling queries

m h sesquile at gmail.com
Wed Dec 5 07:58:55 CET 2007


On Dec 4, 2007 12:56 PM, m h <sesquile at gmail.com> wrote:
> Since the query is confidential I can't really put it here, but I can
> describe it.  I'm pulling stuff out of my fact table and two other
> dimension tables.  The select clause sums a few columns, and on one
> sums the product of one column and the sum of a few others.  The
> coalesce function is used to convert NULLs to 0.  The where statement
> joins the tables using the = operator and then has two "IN" clauses.
> Then there is a group by (since I'm aggregating in the select) and an
> order by.
>
> Any hints on how to increase performance?  Do I need to tune my query
> or tweak other things?  (Yes I know the laptop machine is not apples
> to apples to the vmware machine)
>
> Am open to suggestions.
>

In the meantime I've done the following in an attempt to make the
query faster all to no avail (ie the speed stays the same):

  * Remove the calculation doing summing and coerce'ing
  * Change IN statement to =
  * Remove primary KEY for date table and join date table with between
clause (actually surprised this didn't make it slower)
  * Added indexes for non-PK columns I'm joining on.  No difference!

Does this have something to do with the tables in the "tmp" schema?
Does it make queries slower?

cheers,

-matt




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