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Posted to dev@jena.apache.org by Andy Seaborne <an...@apache.org> on 2014/05/24 20:44:08 UTC
Change to the optimizer : property path expansion to happen early
Rob,
As part of JENA-631 (Property paths not executing property functions), I
found that the translation of simple property paths was happening very
late in the optimization sequence transformations.
Uses of sequence :p/:q expand to triple patterns. If this is done late,
earlier optimizations see property paths and not triple patterns.
One of those happens to be the transform that inserts property functions.
I've moved the property path flattening to be the first transform of
note. Hopefully this does nothing but improve the situation but it's a
delicate balance hence pointing it out..
Andy
Re: Change to the optimizer : property path expansion to happen early
Posted by Andy Seaborne <an...@apache.org>.
Rob,
Good point about property functions being turned off.
I reviewed the determining code in PathEngine and whether its off in the
context, or the PropertyFunction registry has been emptied, or specific
functions removed, then the code will not process property functions in
property paths.
The reordering the optimizaer will shoudl only affect you in that some
optimizations may occur where :p/:q was used and is now expanded into
the triple pattern only form right at the start of optimization.
Andy
On 27/05/14 09:03, Rob Vesse wrote:
> Sounds like a sensible change to me for ARQ and TDB
>
> We don't support property functions in Urika so we turn off that
> optimisation in our optimiser so will likely make no difference to us there
>
> Thanks for the heads up,
>
> Rob
>
> On 24/05/2014 19:44, "Andy Seaborne" <an...@apache.org> wrote:
>
>> Rob,
>>
>> As part of JENA-631 (Property paths not executing property functions), I
>> found that the translation of simple property paths was happening very
>> late in the optimization sequence transformations.
>>
>> Uses of sequence :p/:q expand to triple patterns. If this is done late,
>> earlier optimizations see property paths and not triple patterns.
>>
>> One of those happens to be the transform that inserts property functions.
>>
>> I've moved the property path flattening to be the first transform of
>> note. Hopefully this does nothing but improve the situation but it's a
>> delicate balance hence pointing it out..
>>
>> Andy
>
>
>
>
Re: Change to the optimizer : property path expansion to happen early
Posted by Rob Vesse <rv...@dotnetrdf.org>.
Sounds like a sensible change to me for ARQ and TDB
We don't support property functions in Urika so we turn off that
optimisation in our optimiser so will likely make no difference to us there
Thanks for the heads up,
Rob
On 24/05/2014 19:44, "Andy Seaborne" <an...@apache.org> wrote:
>Rob,
>
>As part of JENA-631 (Property paths not executing property functions), I
>found that the translation of simple property paths was happening very
>late in the optimization sequence transformations.
>
>Uses of sequence :p/:q expand to triple patterns. If this is done late,
>earlier optimizations see property paths and not triple patterns.
>
>One of those happens to be the transform that inserts property functions.
>
>I've moved the property path flattening to be the first transform of
>note. Hopefully this does nothing but improve the situation but it's a
>delicate balance hence pointing it out..
>
> Andy