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Top 10 Interview Questions for Neo4j Graph Database

Q1. Explain what is Neo4j?

Ans: Neo4j is an open source NOSQL graph database, carried out in Java. It saves information based in graphs instead of in tables.

Q2. For what Neo4j is extensively used for?

Ans: Neo4j is extensively used for

Highly connected facts – Social Network

Recommendation- ( e-coomerce)

Path Finding

Data First Schema (bottom-up)

Schema Evolution

A* (Least Cost Path)

Q3. What can you delete databases in Neo4J?

Ans: If you need to delete/get rid of whole graph directory you may use command rm -rf statistics/*as such Neo4j isn't storing anything out of doors that.

Q4. Mention some of the essential characteristics of neo4j?

Ans: Some crucial characteristics of neo4j includes

Materializing of relationship at advent time, ensuing in no penalties for runtime queries

Continuous time traversals for dating inside the graph both in breadth and intensity because of double linking at the storage level between nodes and relationships

Relationship in Neo4j is speedy and give the opportunity to materialize and use new relationships afterward to “shortcut” and speed up the area facts whilst new requirement get up

It can do memory caching for graphs and offers compact garage, ensuing in green scale-up

It is written at the pinnacle of JVM

Q5. Explain the position of building blocks like Nodes, Relationships, Properties and Labels in Neo4j?

Ans: The role of constructing blocks

Nodes: They are entities

Relationship: It connects entities and shape area

Properties: It includes meta-data and attributes

Labels: It group nodes by role

Q6. Explain how you can run CQL commands in Neo4j?

Ans: You use “$” set off to run all CQL commands in Neo4j.

Q7. Mention what are the one-of-a-kind forms of object caches in Neo4j?

Ans: There are one of a kind varieties of object caches in Neo4j

Reference Caches: With this cache, Neo4j will use as an awful lot as allotted JVM heap memory as it can preserve nodes and relationships

High-overall performance Caches: It get assigned a certain maximum amount of space at the JVM heap and will delete items whenever it grows bigger than that.

Relationship and Nodes are brought to the object cache as quickly as they're accessed

Q8. Mention which query language does Neo4j use and what is encompass?

Ans: Neo4j makes use of Cypher query language, that is particular to Neo4j. Traversing the graph calls for to recognise where you want to begin (Start), the guidelines that permit traversal (Match) and what information you're anticipating returned (Return). The primary query consists of

START n

MATCH n-[r]- m

RETURN r;

Q9. Is it feasible that with Neo4j you may query it over the internet?

Ans: As such Neo4j got RESTful API, you may query over the internet, or you may run it regionally. It runs inside the Heroku or Cloud.

Q10. Explain how you can create/delete databases in Neo4j?

Ans: To delete/cast off whole graph directory you could use command rm –rf statistics/* as such Neo4j is not storing something outside that.

Q11. Explain how Neo4j may be useful in detecting Brute Force Attack?

Ans: Neo4J permits to keep and retrieve more than one complex relations. The functionality of Neo4j to do complex question in actual time is truly beneficial in figuring out a brute force attack lots faster. The most essential factor in detecting such attacks is to seize sufficient information approximately every requests like

Client actual IP deal with and no longer the proxy one

Timestamp

Q12. Mention how indexing is performed in Neo4j?

Ans: There became no indexing in in advance days for Neo4j, however later on it become introduced with new feature Automatic Indexes via using the command

START n=node:node_auto_index(name=‘abc’) RETURN n

Q13. Mention how documents are saved in Neo4j?

Ans: Neo4j shops graph facts in some of unique save documents, and each shop report includes the statistics for a specific part of the graph for example relationships, nodes, residences and so on. For example Neostore.Nodestore.Db, neostore.Propertystore.Db and so forth.

Q14. Mention what Neo4j CQL command is used for?

Ans: Neo4j CQL command may be used for

To create nodes with and without houses

To create a dating between nodes with houses

To create a courting between nodes with out residences

To make more than one or unmarried labels to a Node or a Relationship

Q15. Explain what Neo4j CQL MATCH command is used for?

Ans: The CQL MATCH command in NEO4j is used for

To get data about homes and nodes from the database

To get information approximately dating, nodes and houses from the database

Q16. Explain what is the MATCH command syntax and what's the rule for the use of it?

Ans: The syntax for MATCH command is

MATCH

(

<node-name>:<label-name>

)

The rule for the use of MATCH command is that you can't use this command by myself to fetch information from the database in any other case it'll display invalid syntax error.

Q17. Explain what does the SET clause is used for in Neo4j?

Ans: Neo4j CQL use SET clause for the subsequent purpose

Update or Add properties values

Add new homes to present Relationship or Node

Q18. Explain what Neo4j CQL LIMIT clause is used for?

Ans: Neo4j CQL LIMIT clause is used for restrict or clear out the quantity of rows go back by a query.

Q19. Mention the IN Operator syntax in Neo4i?

Ans: The IN Operator syntax in NEO4j could be something like this

IN[ <Collection-of-values>]

Q20. Explain how Neo4j stores primitive array?

Ans: Neo4j stores primitive array in a compressed manner so as to store the space on disk, to try this it makes use of a “bit saving” set of rules.

Q21. Why Neo4J is known as graph database?