My understanding is that it's the compound predicate that we're supposed to avoid, equating to something like another join in the logic.
-W From: general-boun...@developer.marklogic.com [mailto:general-boun...@developer.marklogic.com] On Behalf Of seme...@hotmail.com Sent: Thursday, October 20, 2011 10:33 AM To: general@developer.marklogic.com Subject: Re: [MarkLogic Dev General] results returning faster when using string instead of integer in predicate Ok that makes sense. Also, slightly different, but interesting to me, is the speed results from compound predicates: /image[sizes[size/@w = "98"]] ~ PT0.016S /image[sizes[size[@w = "98"]]] ~ PT0.031S Either having a third level compound predicate or having an attribute as the first step in the predicate makes the difference in this case. Not sure which. > From: m...@blakeley.com > Date: Thu, 20 Oct 2011 10:27:40 -0700 > To: general@developer.marklogic.com > Subject: Re: [MarkLogic Dev General] results returning faster when using > string instead of integer in predicate > > Consider this: > > attribute w { 123.0 } = 123 > => true > > If the RHS 123 were converted to string, this would return false because > "123.0" != "123". So 123 isn't being converted to string. Rather, every @w > must atomize to a numeric type. That seems to be a little more expensive than > atomization to string. > > -- Mike > > On 20 Oct 2011, at 10:21 , seme...@hotmail.com wrote: > > > Given a few thousand XML files in the DB that look like this: > > > > <thing> > > <sizes> > > <size w="123"/> > > <size w="456"/> > > </sizes> > > </thing> > > > > with no schema being used, I get different speed results depending on > > whether I use a string or integer value in the predicate: > > > > /thing[sizes/size/@w = 123] > > > > ~ PT0.031S (average) > > > > > > /thing[sizes/size/@w = "123"] > > > > ~ PT0.016S (average) > > > > > > Is this because the values in the XML file are stored are a string > > (codepoint values) and when the predicate uses an integer it must be > > converted into a string? Or is there something else going on? > > > > thanks, > > Ryan > > _______________________________________________ > > General mailing list > > General@developer.marklogic.com > > http://developer.marklogic.com/mailman/listinfo/general > > _______________________________________________ > General mailing list > General@developer.marklogic.com > http://developer.marklogic.com/mailman/listinfo/general
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