RavenDB Interview Questions

RavenDB is a NoSQL based document-oriented, fully transactional database. RavenDB can perform 1 million reads and 150000 writes per second.

RavenDB provides for the following features:

• Performance: RavenDB can achieve 100,000 writes per second. Moreover, one million reads can be done on commodity hardware. RavenDB is developed with Voron, a custom-made storage engine, which enhances RavenDB’s performance.
• Studio Management: RavenDB’s Graphic user interface makes its’ users experience fun for both experts and non-expets. It’s one of part of any license that includes user’s free community version.
• Fully Transactional: RavenDB is a non-relational database, first of its kind. It can achieve ACID across the entire database and maintain the features of any SQL while taking user’s capacity to the next level.
• Multi-Model Architecture: RavenDB engages well with other relational databases, giving its users the opportunity to use any NoSQL layer along with RavenDB
• Multi-Platform: RavenDB can work on Windows, Windows Tablet, Linux, MACOS as well as Raspberry platforms.
• High Availability: RavenDB is break free of the single server bottleneck. It can set up a distributed data cluster in a small amount of time as well as replicate user’s database in real time so users can be everywhere at the same time, and always available to their clients.
• Ease of Use: RavenDB is very easy to install, can be simply secured, and can be learned fast. The query language of RavenDB is mostly SQL. Using any training resources, one can become an expert in just a few days time.
• Specially designed: Users can spend more time coding and less time finding support. RavenDB comes with ways to help its user’s self-solve problems and minimize overhead.  

The main advantages of using RavenDB are as follows:

• RavenDB is mainly written in C and .NET, and therefore it is easy to understand how to use it. This is one best advantage. Data can be efficiently queried with the help of LINQ queries from .NET code or by using RESTful that is REpresentational State Transfer APIs.
• In RavenDB, the database schema is not fixed for long; instead, data is stored without schema in the form of JSON documents. Thus the documents have many arbitrary structures as well as attributes which are associated with them. Inside, RavenDB makes the best use of Indexes, which are automatically created which depends on user’s usage or are created explicitly by the clients.
• RavenDB is very scalable and can be built for web scaling. It thus offers replication along with sharding support, which is quite extraordinary.
• RavenDB comes with the ACID support properties.

RavenDB launching can be done in the following modes. It can be launched in:

• Console mode: This is the mode best suitable for learning and testing.
• Hosted by IIS (Internet Information Server): This mode is the most common one to run RavenDB in a production environment.
• Windows Service Mode:  RavenDB creates its own HTTP server and then process requests of the users internally.
• Embedded mode: In this mode, RavenDB is embedded in user’s application and may run completely in memory itself.

There are two types of authentication methods in RavenDB:

• Windows authentication: This is the authentication method, which is chosen when a request by the client needs to be authenticated and any other authentication method cannot be detected.
• OAuth authentication: OAuth is an authorization framework, which enables the application to obtain limited access to an HTTP service, which may be on behalf of a resource owner or by allowing the application to obtain access on behalf of its own.

RQL stands for Raven Query Language is similar to any SQL language.It is used to get the data from the server when any queries are being executed.It is specially designed to take out from outside any query pipeline of RavenDB in such a way that is easy to understand, simple to use, and not hard to work for the user.

Keywords and methods available in RQL are:

• DECLARE,
• FROM,
• INDEX,
• GROUP BY array()
• WHERE id(), search(), cmpxchg(), boost(), regex(), startsWith(), endsWith(), lucene(), exists(), exact(),intersect(), spatial.within(), spatial.contains() , spatial.disjoint(), spatial.intersects(),moreLikeThis()
• ORDER BY (ASC | ASCENDING, DESC | DESCEDING)
• AS(string, long,double, alphaNumeric, random(), score(),spatial.distance())
• LOAD
• SELECT=
• DISTINCT (key (), sum (), count (), facet ())
• UPDATE
• INCLUDE

Following operators are also used:

>=, <=, <> or !=, <, >,= or ==, BETWEEN, IN, ALL IN, OR,AND, NOT, (, )

The keyword declares provides the users the ability to create any JS function, which can be reused with the help of select (that is when the projection is done)

The keyword from is used to find the source data that is to be used when any query is executed. 

The keyword group by is used to create an aggregation query.

RavenDB uses collations for sorting as well as indexing documents. Users can set up any specific collation for an index field so that they can sort the data based on any culture-specific rules.
Binary operators in RavenDB are used to build many complex statements.
The NOT operator can be used only with one of the other binary operators thereby creating either OR NOT or AND NOT ones.

JavaScript Object Notation

The RavenDB Management Studio is an integrated and graphical environment, which helps in accessing administering, managing, and configuring the RavenDB server.