Neo4J Interview Questions and Answers
Question - 1 : - What is Neo4J?
Answer - 1 : - It is an open-source graph database used to connect rich data to get connected using graph powered systems in order to deliver accurate connectedness of available data. NOSQL is used to get data connected, with Java and scala implementation.
Question - 2 : - Where do we use Neo4J?
Answer - 2 : - While working with huge distributed databases.
Question - 3 : - Mention some important features of Neo4J
Answer - 3 : - Following are few important features:
• Data Representation using graph model
• Reliable ACID transactions.
• Quick and Durable.
• High Speed query execution for traversals.
• Easily accessible by REST or Java APIs.
Question - 4 : - What is the Query Language used by Neo4J?
Answer - 4 : - Cypher Query Language - CQL is used to execute queries for Neo4J.
Question - 5 : - What kind of language is CQL?
Answer - 5 : - There are two types of query languages - Procedural and declarative.
CQL is a Declarative Language.
Question - 6 : - Mention few other famous graph database available?
Answer - 6 : - Other available graph databases in the market are:
• Oracle NoSQL Database
• Sqrrl Enterprise
• Graph Story
• Titan
• Velocity Graph
• InfoGrid
• Bitsy
• Teradata Aster
• Oracle Spatial and Graph
• Info Grid and many more.
Question - 7 : - List out some of the Neo4J Commands you use.
Answer - 7 : - There are many commands in Neo4J, of which following are few basic commands:
• CREATE - To create a node or relationship.
• MATCH - To read or retrieve all the nodes in the database.
• MERGE - Combination of CREATE and MATCH.
• SET - To add or update properties to new or existing node/relationships.
• CREATE UNIQUE - To mention unique constraints in order to avoid redundant values.
Question - 8 : - What is REMOVE command used for?
Answer - 8 : - To remove labels and properties of the nodes, we use REMOVE.
Question - 9 : - What is the difference between REMOVE and DELETE commands?
Answer - 9 : - The main difference is that REMOVE is for labels and properties of nodes, whereas DELETE is to remove nodes and relationships.
Question - 10 : - What is object Cache in Neo4J?
Answer - 10 : - In order to improve the performance of the graph traversals, Object Cache is used to cache the nodes and their properties