Greetings Neo4j!
I am currently trying to build a search application on top of SNOMED CT international FULL RF 2 Release. The database is quite huge and I had decided to move on with a full text search index for optimal results. So there are primarily 3 types of nodes in a SNOMED CT database :
ObjectConcept
Descriptions
Role Group
There are multiple relationships between the nodes but I'm focussing on that later.
Currently I'm focussing on searching for ObjectConcept Nodes by a String property value called FSN which stands for fully specified name. For this I tried two things :
Create text indexes on FSN : After using this with MATCH queries the results were rather slow even when I was using the CONTAINS predicate and limiting return value to 15.
Create Full Text Indexes: According to the docs, the FT indexes are powered by Apache Lucene. I creaded this for FSN. After using the FT Indexes and using AND clauses in the search term, for example :
>Search Term : head pain
>Query Term: pain AND headache
I observe quite impressive benefits in query time using the profiler in neo4j browser(around from 43ms to 10ms for some queries) however once I start querying the db using the apollo server, query times go as high as 2s - 3s.
The query is as follows, implemented by a custom resolver in neo4j/graphql and apollo-server:
const session = context.driver.session()
let words = args.name.split(" ");
let compoundQuery = "";
if (words.length === 1) compoundQuery = words[0];
else compoundQuery = words.join(" AND ");
console.log(compoundQuery)
compoundQuery+= AND (${args.type})
return session
.run(
`CALL db.index.fulltext.queryNodes('searchIndex',$name) YIELD node, score
RETURN node
LIMIT 10
`,
{ name: compoundQuery }
)
.then((res) => {
session.close()
return res.records.map((record) => {
return record.get('node').properties
})
})
}
I have the following questions:
Am I utilising FT indexes as much as I can or am I missing important optimisations out?
I was trying to implement elasticsearch with neo4j but I read elasticsearch and the FT indexes are both powered by lucene. So am I likely to gain improvements from using elasticsearch? If so? how should I go about it considering that I am using neo4j aura db and my graphql server is on ec2. I am confused as to how to use elasticsearch overall with the GRANDStack. Any help would be appreciated.
Any other Suggestions for optimising search would be greatly appreciated.
Thanks in advance!
