[Mondrian] Re: Performance degradation

Matt Campbell mkambol at gmail.com
Wed Mar 4 08:54:04 EST 2009


I've been trying to isolate when this issue was introduced, but am
struggling a bit with perforce.  I'm trying to sync to a changelist using
something like:
p4 sync //open/mondrian/... at 10480

This brings in the set of files from that changelist, but does not appear to
delete files from future changelists.

What is the correct way to sync to a changelist?


On Tue, Mar 3, 2009 at 6:47 PM, Matt Campbell <mkambol at gmail.com> wrote:

> Hi peter- this query was run *without* native nonempty turned on.
>
> On 3/3/09, Peter Tran <ptran at prospricing.com> wrote:
> > Matt,
> >
> > Are you doing native evaluation?  We found a case where Mondrian was
> doing
> > non-native evaluation based on how the MDX was structured which had a
> huge
> > impact on performance.
> >
> > Check to see whether the crossjoin is being pushed down natively to the
> > database.
> >
> > -Peter
> >
> > ________________________________
> > From: mondrian-bounces at pentaho.org [mailto:mondrian-bounces at pentaho.org]
> On
> > Behalf Of Matt Campbell
> > Sent: Tuesday, March 03, 2009 4:25 PM
> > To: Mondrian developer mailing list
> > Subject: [Mondrian] Re: Performance degradation
> >
> > I was able to reproduce this issue with a very simple Foodmart query.
>  The
> > following runs in under 2 seconds with changelist 10915.  It now takes
> > around 55 seconds with 12403.   From the little investigation I've done
> it
> > looks like most time is spent in executeStripe().
> >
> > It's interesting, if I eliminate either part of the set the time drops
> back
> > down to ~2 seconds--i.e. eliminate either the GENERATE() or the
> > {Product.DEFAULTMEMBER, [Yearly Income].DEFAULTMEMBER}.  If they are both
> > present, though, it takes 55 seconds.
> >
> > SELECT
> >             {GENERATE({[Product].[Product Name].MEMBERS},
> >              CROSSJOIN( {([Product].CURRENTMEMBER)},
> >            {[Yearly Income].[Yearly Income].MEMBERS}), ALL),
> >             {([Product].DEFAULTMEMBER,[Yearly Income].DEFAULTMEMBER)}
> > }
> >  ON AXIS(0)
> > FROM
> >             [Sales] ;
> >
> >
> > On Tue, Mar 3, 2009 at 11:03 AM, Matt Campbell
> > <mkambol at gmail.com<mailto:mkambol at gmail.com>> wrote:
> >
> > During a run of a performance test we noticed a fairly significant
> increase
> > in query time for queries involving very large numbers of cells.  We
> > actually hadn't run this particular test in nearly a year, so the
> comparison
> > is between changelist 10915 and 12403.
> >
> > The query is ridiculously large--nearly 200K tuples, intersected with 12
> > measures.  With 10915 this query ran in a little over an hour.  With
> 12403
> > it runs for over 5 hours.
> >
> > I haven't investigated much yet.  I'm going to create simple Foodmart
> query
> > to try to reproduce, and then I'll try to narrow down where the
> bottleneck
> > is.  I wanted to post, though, in case anyone has thoughts about this.
> >
> >
> >
> >
>
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