Thanks Michael! ~A
On Mon, Oct 13, 2014 at 6:57 PM, Michael Hunger < michael.hun...@neotechnology.com> wrote: > The more recent versions use and index for your IN query, so it will > actually use an index or constraint in this case, that fix was added after > 2.0.3 though. > > > > On Mon, Oct 13, 2014 at 11:33 PM, Aru Sahni <arusa...@gmail.com> wrote: > >> Hi, >> >> Disclaimer: I'm using Neo4j 2.0.3. I know that this is far from the most >> recent version, but a bug between the latest stable py2neo and 2.1.x >> builds have me stuck on this release >> <https://groups.google.com/forum/#!topic/neo4j/-eqzLPxk0DI>. >> >> I'm writing an ETL script that needs to retrieve around 500 nodes per >> request. My nodes have a `uid` field that is indexed and has a >> uniqueness constraint. >> >> :Entity(uid) >> >> To get these nodes, I'm issuing the following query: >> >> MATCH (n:Entity) >> WHERE n.uid IN ["uid001", "uid002" ... "uid500"] >> RETURN n ORDER BY ID(n) ASC; >> >> This takes quite a bit of time. Running this with the profiler indicates >> that it's hitting the database for every filter. Attempting to unroll this >> (i.e. `WHERE n.uid = "uid001" OR n.uid = "uid002"`, etc) hits the >> database just as heavily. If I try to specify the index with the USING >> statement, I get the following error: >> >> IndexHintException: Cannot use index hint in this context. Index hints >>> require using a simple equality comparison in WHERE (either directly or as >>> part of a top-level AND). >>> >> >> What I find ends up working is: >> >> MATCH (n:Entity) WHERE n.uid = "uid001" RETURN n >> UNION ALL >> MATCH (n:Entity) WHERE n.uid = "uid002" RETURN n >> ... >> MATCH (n:Entity) WHERE n.uid = "uid500" RETURN n >> >> This is a little too verbose and hacky for my tastes. I was wondering if >> there's anything I can do to improve the performance and reduce the >> complexity of this query. >> >> Regards, >> ~Aru >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Neo4j" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to neo4j+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to neo4j+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to neo4j+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
