pagination - Cypher SORT performance -

i'm trying accomplish pretty common task. have substantial dataset in neo4j database and, restful web service, want return data in chunks of 25 nodes. model quite simple:

(:tenant {hash:''})-[:owns]->(:asset {hash:'', name:''}) 

i have unique constraints on hash properties on both labels.

if wanted obtain 101th data page, cypher query this:

match (:tenant {hash:'foo'})-[:owns]->(a:asset) return order a.hash skip 2500 limit 25 

my dataset consists of single tenant, ~75k assets. above query takes ~30(!) seconds complete. notice further advance in data (ie. higher skip) longer takes query return.

i figured out culprit of performance issues order a.hash. when remove it, query returns sub-second results. quite surprise, i'd expect index ordered.

obviously, in order implement sensible pagination, must have consistent sort order.

• any tips on making query perform?
• alternative suggestions paging? can see adding dedicated page nodes, become difficult maintain.
• what default sort order anyway, , consistent?

hey @geoffreybraaf found time week @ issue, right, there implementation issue made unnecessarily slow.

i used timmy's suggestion implement java version finished in 30ms. cypher version took 100 seconds. working on implementation of top-n select in cypher improved massively factor of 600. cypher takes 150ms query.

see: https://gist.github.com/jexp/9954509

the work merged in 2.0-maint , released part of 2.0.2

see: https://github.com/neo4j/neo4j/pull/2230