Neo4j interview questions and Answers
Most Frequently Asked Neo4j interview questions
In Neo4j, the object cache caches individual relationships and nodes and respectively their properties in a form which is optimized for traversal of the graph. Here contents of this cache are objects with a representation geared towards the Neo4j supporting object API and graph traversals.
In Neo4j, an index is a redundant copy of data in the database purposed of making related data searches more efficient. It comes with the cost of additional storage space and slower writes, so deciding what to index and what not to is a crucial and often non-trivial task for users.
The MATCH command allows developers to specify patterns that Neo4j will search for in the database. This is the original way of getting data into the current set of buildings. It’s often paired with a WHERE clause which predicates or adds restrictions to the MATCH command.
- Neo4j CQL MATCH command – used to get data about nodes and properties
MATCH
(
<node-name >:<label-name>
)
- Delete all nodes and relationships command:
To create a new database in Neo4j without removing your existing one, users can directly edit the neo4j.conf file in their conf directory of their $NEO4J_HOME. Search dbms.active_database= and replace it with your desired name and restart the program again. A new database will be created now.
To delete a node in Neo4j, we have to use the DELETE clause. It also can be used to delete
relationships or paths. The syntax will be as following to delete a single node:
MATCH (n:Person { name: 'UNKNOWN' })
DELETE n
To delete all nodes:
MATCH (n)
DETACH DELETE n
The Set clause in Neo4j can be used to add new properties to an existing relationship or node. It can
also be used to update or add existing properties values. To set a property in a node, here is
syntax:-
MATCH (node:label{properties . . . . . . . . . . . . . . })
SET node.property = value
RETURN node