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1. Explain What Is Dynamodb?

It is a NoSQL database carrier that's superintendent and affords rapid and inevitable performance with seamless scalability.
It also enables the users to dump the operating and scaling disbursed databases to AWS.
So that the customers don’t ought to worry about setup and configuration, hardware provisions, replication, throughput potential making plans, cluster scaling or software patching.

2.List Some Benefits Of Using Amazon Dynamodb?

Here is the listing of some of the benefits of the usage of Amazon DynamoDB: 

  • It is a managed service where there is no need to lease the experts or worry about set up, setup, cluster and so forth.,

  • It is scalable.

  • It presents the customers excessive throughput at very low latency.

  • It is durable and pretty available.

  • It is flexible and permits dynamic tables advent that consists of multi-valued attributes.

  • It is cost-effective.

3. What Are The Non-relational Databases?

The Non-Relational databases are NoSQL databases.These databases are labeled into 4 businesses. They are:

  • Key-fee shops

  • Graph shops

  • Column shops

  • Document shops 

4.Explain What Is Dynamodb Mapper Class?

It is the access point to DynamoDB.The DynamoDB Mapper magnificence gives access to a DynamoDB endpoint and allows the user to get entry to to their records in diverse tables, execute queries and test towards tables, and carry out CRUD operations on items.

5. List The Data Types Supported By Dynamodb?

DynamoDB supports four scalar statistics sorts, and they may be:

  • Number

  • String

  • Binary

  • Boolean

 DynamoDB supports collection records sorts consisting of:

  • Number Set

  • String Set

  • Binary Set

  • Heterogeneous List

  • Heterogeneous Map

DynamoDB also supports Null values.

6. What kind of query functionality does DynamoDB support?

  • It supports GET/PUT operation using the user-defined primary key.

  • It provides flexible querying by letting query a non-primary key attribute using local secondary indexes and Global secondary indexes.

  • It allows quick reads and writes data for an item associated with single attribute partition primary key.

  • It allows you to use the Query API to retrieve all the items for a single composite partition-sort key across a range of sort keys.

7. Does Amazon DynamoDB support conditional operations?

For an operation to be completed on an item, you have to specify a condition.
You can define a ConditionExpression that can be constructed from the following:


  • Comparison operators: =, <>, <, >, <=, >=, BETWEEN, and IN

  • Logical operators: NOT, AND, and OR. 

You can also construct a free-form conditional expression that combines multiple conditional clauses which also includes nested clauses.

8. List some difference between Amazon DynamoDB and Amazon SimpleDB?

  • Amazon DynamoDB : It is a fast and scalable NoSQL Database Service that is designed for internet scale applications, to maintain predictably high performance and to be highly cost-effective for workloads of any scale, on the top of all it is highly recommended.

  • Amazon SimpleDB : It has scaling limitations and is a good fit for smaller workloads that requires query flexibility.It automatically indexes all item attributes and supports query flexibility at the cost of performance and scale.


9. What Amazon DynamoDB BatchWriteItem API does?

The Amazon DynamoDB BatchWriteItem inserts, deletes and replaces multiple items across multiple tables in just one request, but not in one transaction.
With maximum total request size of 16 MB, it supports batches of up to 25 items to insert or delete.

10. Please explain key-value store?

It is a database service that provides and supports storing, updating and querying the objects that are identified using key and values that constitutes the actual content that is being stored.

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