What is DynamoDB streams used for?

DynamoDB Streams captures a time-ordered sequence of item-level modifications in any DynamoDB table and stores this information in a log for up to 24 hours. Applications can access this log and view the data items as they appeared before and after they were modified, in near-real time.

What is DynamoDB LSI?

A local secondary index maintains an alternate sort key for a given partition key value. A local secondary index also contains a copy of some or all of the attributes from its base table. You specify which attributes are projected into the local secondary index when you create the table.

How does DynamoDB stream work?

When you enable DynamoDB Streams, it captures a time-ordered sequence of item-level modifications in a DynamoDB table and durably stores the information for up to 24 hours. Applications can access a series of stream records, which contain an item change, from a DynamoDB stream in near real time.

Does Kinesis use DynamoDB?

Amazon Kinesis Client Library (KCL) for Java | Python | Ruby | Node. NET automatically creates an Amazon DynamoDB table for each Amazon Kinesis Application to track and maintain state information such as resharding events and sequence number checkpoints.

Can I delete LSI DynamoDB?

DynamoDB Local Secondary Index (LSI) That also means that they can be created only on tables with composite primary key. Additionally, LSIs: Limit you to only 10GB of data per Hash/Partition Key. They have to be specified at table creation – you can’t add or remove them after provisioning the table.

Is DynamoDB NoSQL?

DynamoDB is a proprietary NoSQL database service built by Amazon and offered as part of the Amazon Web Services (AWS) portfolio. The name comes from Dynamo, a highly available key-value store developed in response to holiday outages on the Amazon e-commerce platform in 2004.

What is DynamoDB based on?

Amazon DynamoDB is based on the principles of Dynamo, a progenitor of NoSQL, and brings the power of the cloud to the NoSQL database world. It offers customers high-availability, reliability, and incremental scalability, with no limits on dataset size or request throughput for a given table.

How do I use DynamoDB?

Getting Started with DynamoDB

1. Basic Concepts in DynamoDB.
2. Prerequisites – Getting Started Tutorial.
3. Step 1: Create a Table.
4. Step 2: Write Data to a Table Using the Console or AWS CLI.
5. Step 3: Read Data from a Table.
6. Step 4: Update Data in a Table.
7. Step 5: Query Data in a Table.
8. Step 6: Create a Global Secondary Index.

What does a projection expression do in DynamoDB?

Amazon DynamoDB returns all the item attributes by default. To get only some, rather than all of the attributes, use a projection expression. A projection expression is a string that identifies the attributes that you want. To retrieve a single attribute, specify its name. For multiple attributes, the names must be comma-separated.

How are attributes projected into the DynamoDB index?

The set of attributes that are projected into the index: KEYS_ONLY – Only the index and primary keys are projected into the index. INCLUDE – Only the specified table attributes are projected into the index. The list of projected attributes is in NonKeyAttributes . ALL – All of the table attributes are projected into the index.

How to read a table in Amazon DynamoDB?

To read data from a table, you use operations such as GetItem , Query, or Scan. Amazon DynamoDB returns all the item attributes by default. To get only some, rather than all of the attributes, use a projection expression.

How are key expressions used in DynamoDB query?

use key expressionsto limit Items based on the RANGE key; and use projection expressions to narrow the responsefor your Query. Before reading this section, you should understand DynamoDB expressions. Retrieving All Items with a Given Partition Key In our previous chapter, we looked at working with individual Items at a time.