Neo4J Interview Questions and Answers
Question - 21 : - How files are stored in Neo4J?
Answer - 21 : -
Neo4J stores graph data in a number of different store files, and each store file contains the data for a specific part of the graph for example relationships, nodes, properties etc.
Question - 22 : - What is the use of SET clause in Neo4J?
Answer - 22 : -
SET clause is used to add new properties to an existing node or relationship.
Question - 23 : - What is MATCH command? Where is it used in Neo4J?
Answer - 23 : -
MATCH command is used with RETURN or UPDATE clause. It cannot be used alone otherwise it will give error.
Syntax:
MATCH
(
:
)
The MATCH command cannot be used alone to fetch data from the database otherwise it will show invalid syntax error.
Question - 24 : - What are the different Neo4J CQL command?
Answer - 24 : -
Following the different Neo4J CQL commands:
- Create
- Match
- Delete
- Merge
- Set
- Remove
- Return etc.
Question - 25 : - Is it possible to query Neo4j over the internet?
Answer - 25 : -
As such Neo4j got RESTful API, you can query over the web, or you can run it locally. It runs in the Heroku or Cloud.
Question - 26 : - Mention some of the important characteristics of neo4j?
Answer - 26 : -
Some important characteristics of neo4j includes
- Materializing of relationship at creation time, resulting in no penalties for runtime queries
- Continuous time traversals for relationship in the graph both in breadth and depth due to double linking on the storage level between nodes and relationships
- Relationship in Neo4j is fast and make it possible to materialize and use new relationships later on to “shortcut” and speed up the domain data when new requirement arise
- It can do memory caching for graphs and provides compact storage, resulting in efficient scale-up
- It is written on the top of JVM
Question - 27 : - Explain the role of building blocks like Nodes, Relationships, Properties and Labels in Neo4j?
Answer - 27 : -
The role of building blocks
- Nodes: They are entities
- Relationship: It connects entities and structure domain
- Properties: It consists of meta-data and attributes
- Labels: It group nodes by role
Question - 28 : - Explain how you can run CQL commands in Neo4j?
Answer - 28 : -
You use “$” prompt to run all CQL commands in Neo4j.
Question - 29 : - Mention what are the different types of object caches in Neo4j?
Answer - 29 : -
There are two different types of object caches in Neo4j
- Reference Caches: With this cache, Neo4j will use as much as allocated JVM heap memory as it can hold nodes and relationships
- High-performance Caches: It get assigned a certain maximum amount of space on the JVM heap and will delete objects whenever it grows bigger than that.
Relationship and Nodes are added to the object cache as soon as they are accessed
Question - 30 : - Is it possible that with Neo4j you can query it over the internet?
Answer - 30 : -
As such Neo4j got RESTful API, you can query over the web, or you can run it locally. It runs in the Heroku or Cloud.