I presume you have an index / constraint on nodeType1.fullname AND
nodeType1.name?!
not sure why you do the pattern match first and only then the property
lookup.
What version are you using? in Neo4j 3.1 for the query below you should see
much better performance:
match (ea:nodeType1 {name:"something1"})<-[:maps_to*]-(eb:nodeType1)
where eb.fullname starts with "something"
with distinct ea, eb
return ea.name <http://el.name/>, eb.name <http://et.name/>;
I would also think that shortest-path is much more sensible here:
match (ea:nodeType1 {name:"something1"})
match (eb:nodeType1) where eb.fullname starts with "something"
match shortestPath( (ea)<-[:maps_to*]-(eb) )
with distinct ea, eb
return ea.name <http://el.name/>, eb.name <http://et.name/>;
On Mon, Jan 16, 2017 at 9:19 PM, <[email protected]> wrote:
> Hi, I have a very expensive query that I'm trying to figure out how to
> optimise.
>
> match (ea:nodeType1 {name:"something1"})<-[:maps_to*]-(eb:nodeType1) with
> distinct ea, eb match (eb) where eb.fullname starts with "something" return
> ea.name <http://el.name/>, eb.name <http://et.name/>;
>
> I've used the profiler and as expected the expand all is the most
> expensive part of the operation
>
> +Filter | 128 | 334812480 | 669618290 | |
> +VarLengthExpand(All) | 128 | 669618290 | 1494585385 | |
> (ea)<-[:maps_to*]-(eb)
>
>
> I've used the profiler and brought down the running time from 3 hours to
> 2,15. I then tried the enterprise version hoping that the query would use
> the available processors but it used only one so I'm assuming that cypher
> is not parallelizable.
>
> Is there some quick win to speed up a distinct path query or do I have to
> write my own using the java api?
>
> p.s: the query might not compile as I've tried to summarise the gist of
> the issue.
>
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