You need to supply more details, i.e. the queries, query plans, query times, how many labels you have per node etc.
Michael On Fri, Aug 4, 2017 at 7:02 AM, Sun Yuhan <wdmzs...@gmail.com> wrote: > I tested the query like (a:A) --> (b:B) in two graphs. The two graphs have > the same graph structure, which means same number of nodes and edges. The > edges are connecting the same two nodes in the two graphs. The only > difference is that the first graph has only two labels A and B and the > second graph has ten different labels, which is from A to I. For this same > query, query time in the second graph is about 30x worse than that in the > first graph. > > Is there any feasible explanation for this? > > On Thursday, July 6, 2017 at 9:10:24 PM UTC-7, Michael Hunger wrote: >> >> The index lookup is used when using labels with properties >> The label scan store that I described is used for all label scan >> >> Von meinem iPhone gesendet >> >> Am 07.07.2017 um 03:31 schrieb Sun Yuhan <wdmz...@gmail.com>: >> >> Actually I am using the neo4j to execute some graph pattern query ( >> subgraph isomorphism). So the given query pattern will be a labeled graph >> and the results are all subgraphs in the database that can fit the pattern. >> Does the index you mentioned in the reply can achieve better performance >> than using labels? >> >> On Wednesday, July 5, 2017 at 1:32:15 AM UTC-7, Michael Hunger wrote: >>> >>> It should be a rare operation if you have indexes in place >>> >>> There is a reverse store mapping labels to sets of node ids >>> >>> In 3.1 it uses a compressed lucene format >>> In 3.2 a custom generational b+ tree >>> Details for both are only in the source >>> >>> >>> >>> Von meinem iPhone gesendet >>> >>> Am 05.07.2017 um 07:31 schrieb Sun Yuhan <wdmz...@gmail.com>: >>> >>> The NodeByLabelScan is very commonly used in cypher query execution >>> plans. However, it is not clear how this operation is executed in neo4j. >>> >>> What's more, I do not know how the label is managed and stored in neo4j. >>> Are there any materials online that I can refer to? Or I can refer to some >>> source code of neo4j to see the implementation details. >>> >>> -- >>> 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+un...@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+un...@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.
