Thank you @Lvc@,
that's a great improvement!
Can I ask you which computational complexity we can expect from this?
select out('Friend')[67] from #31:40
Is it a O(1) or O(N) where N is the number of edges outgoing from the
vertex?
Another question:
select out('Friend')[name='MONA'] from #31:40
uses indexes?
On Thursday, December 19, 2013 1:05:36 PM UTC+1, Lvc@ wrote:
>
> Hi all,
> in "develop" branch I've just committed a new powerful feature: allow to
> filter collections in chain. To understand it let's go to a couple of
> examples.
>
> *Examples*
>
> *Example 1: Get the first friend of mine*
>
> You can get it by using:
>
> select expand( out ) from (
> select out('Friend') from Profile where name = 'Luca'
> ) limit 1
>
> But now you can also do this:
>
> select out('Friend')*[0]* from Profile where name = 'Luca'
>
> Much easier and faster on execution!
>
> *Example 2: from GratefulDeadConcerts database traverse all the out()
> connection and get the first song called 'MONA'*
>
> select from (
> select expand( out() ) from V
> ) where name = 'MONA' and type = 'song' limit 1
>
> @rid @version @class name in_followed_by song_type performances
> typeout_followed_byout_sung_byout_written_by
> #9:6<http://localhost:2480/studio/index.html#/database/GratefulDeadConcerts/browse/edit/9:6>19VMONA[2]cover1song[2][1][1]
> Executed in 0.455 seconds.
>
> Now let's use the new way:
>
> select expand( out()*[name='MONA'][type='song']* ) from V
>
> @rid @version @class name in_followed_by song_type performances
> typeout_followed_byout_sung_byout_written_by
> #9:6<http://localhost:2480/studio/index.html#/database/GratefulDeadConcerts/browse/edit/9:6>19VMONA[2]cover1song[2][1][1]
> Executed in 0.106 seconds.
>
> Note last execution, in this case, is 4x faster!
>
> Squared brackets [] allows:
> - filtering by one index, example out()[0]
> - filtering by multiple indexes, example out()[0,2,4]
> - filtering by ranges, example out()[0-9]
> - filtering by equal conditions (only equals is supported), example
> out()[@class = 'Person']
>
> Brackets [] can be chained, in this case it's like filtering by AND
> operator. Look at the Example 2.
>
> For more information about the issue:
> https://github.com/orientechnologies/orientdb/issues/1888
>
>
> Luca Garulli
> CEO at Orient Technologies
> the Company behind OrientDB
> http://about.me/luca.garulli
>
>
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