Can you try to use MERGE instead of MATCH in your relationship-statement that should definitely use the index.
On Wed, Mar 26, 2014 at 10:13 PM, Michel Ávila < [email protected]> wrote: > I have 3 files, containing a set of companies, persons and the > relationships between these entities, respectively. > I managed to load the companies and the persons files in no time, but and > i'm having some performance issues when loading the last one (the > relationships). > It took more than 1 hour and i killed it, because i knew something was not > right. > This sample has following: > > - ~100k companies; > - ~100k persons; > - ~250k relationships; > > I needed to be sure that the file was being read correctly, so i left only > one data row in the "rels" file and ran the following cypher: > > LOAD CSV WITH HEADERS FROM "file:D:\\rels.csv" AS f MATCH (c:company {document > : f.company_document } ) RETURN c > > The result took about 20 seconds to bring me back the company, so it was > not a problem reading the file, but finding the company. > Then i asked the prompt to profile the cypher, and the result was: > > ColumnFilter(symKeys=["f", "c"], returnItemNames=["c"], _rows=1, _db_hits= > 0) > Filter(pred="Property(c,document(3)) == Property(f,company_document)",_rows > =1, _db_hits=112865) > NodeByLabel(identifier="c", _db_hits=0, _rows=112865, > label="company",identifiers > =["c"], producer="NodeByLabel") > LoadCSV(_rows=1, _db_hits=0) > > The way i see it, the loader is reading the entire node set under the > label "company" and applying the document filter later. > When i make the same "MATCH" cypher outside the "LOAD" command, the > profile is this: > > profile MATCH (c:company { document: "76875897000169" } ) RETURN c; > SchemaIndex(identifier="c", _db_hits=0, _rows=1, label="company", query= > "Literal(76875897000169)", identifiers=["c"], property="document",producer > ="SchemaIndex") > > It's clear to me that it's querying the "company" label index as it was > designed to do. > So, why the "LOAD CSV" uses another query plan to do the same lookup? > > Thanks in advance! > > -- > 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 [email protected]. > 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
