The graph looks like this:
A <--- B ---> C
Basically, I want to start with a subset of A vertices and a subset of C
vertices, and I want to get back the subset of B vertices that is linked to
at least 1 vertex in each of the starting subsets.
I actually just tried combining the two queries above, which seems to work
a lot better:
select * from (
traverse out from (
traverse in_D from (
select * from A where aField = 'a456'
)
)
)
where @class = 'B' and (
out_D traverse(0,1) (
@class = 'C' and cField = 'c123'
)
)
Is there a better way to query for those B vertices?
Thanks!
On Friday, January 24, 2014 3:03:25 PM UTC-7, Lvc@ wrote:
>
> Hi Nick,
> can you explain your domain in terms of a graph? Like:
>
> A ---> B <---- C
>
> And where you start and what you want to get back?
>
> Lvc@
>
>
>
> On 24 January 2014 22:00, Nick Bauer <[email protected] <javascript:>>wrote:
>
>> We are using OrientDB 1.6.4.
>>
>> We have a graph with 3 classes of vertices: A, B, and C
>> Class A has a medium multiplicity (tens of thousands of vertices)
>> Class B has a high multiplicity (hundreds of thousands of vertices)
>> Class C has a low multiplicity (a few vertices)
>>
>> We have also defined an edge class, D, which is used to link vertices of
>> all three classes.
>>
>> Every instance of class B is linked to at least one instance of A and at
>> least one instance of C. Also, the links from the B instances are fairly
>> evenly distributed among all of the A instances and among all of the C
>> instances.
>>
>> Thus, there are a relatively small number of B instances linked to any
>> single A instance. There are a much higher number of B instances linked to
>> any single C instance.
>>
>> We want to find all instances of class B that are linked to at least one
>> A instance that has a certain field value and that are also linked to at
>> least one instance of C that has a certain field value.
>>
>>
>> We can solve half of the problem with a query like this, which traverses
>> from the A instances that match the condition, and finds all of the B
>> instances linked to them:
>> select * from (traverse out from (traverse in_D from (select * from A
>> where aField = 'a456') )) where @class = 'B'
>>
>> This query quickly returns a relatively small number of B instances to
>> work with, so it seems beneficial to start there. However,
>> from there, we can continue to traverse out to the C instances linked to
>> those B instances, but it seems like if we do that, we lose the ability to
>> further filter out those B instances based on the C instances they link to.
>>
>> Is there a way to filter the B instances based on the C instances they
>> link to, without traversing to the C instances themselves?
>>
>> We have also found that this query works, but given the high multiplicity
>> of class B, it seems to take a very long time (around 10 minutes) to run:
>> select from B where ((out_D traverse(0,1) (@class = 'C' and cField =
>> 'c123')) and (out_D traverse(0,1) (@class = 'A' and aField = 'a456')))
>>
>> Is there a better way to query for vertices based on their links to
>> multiple collections of vertices?
>>
>> --
>>
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