What is DynamoDBMapper?

What is DynamoDBMapper?

The DynamoDBMapper class is the entry point to Amazon DynamoDB. It provides access to a DynamoDB endpoint and enables you to access your data in various tables. It also enables you to perform various create, read, update, and delete (CRUD) operations on items, and run queries and scans against tables.

What is @DynamoDBTable?

DynamoDBTable. Identifies the target table in DynamoDB. For example, the following Java code defines a class Developer and maps it to the People table in DynamoDB. @DynamoDBTable(tableName=”People”) public class Developer { }

Is DynamoDBMapper thread safe?

This class is thread-safe and can be shared between threads.

What is withScanIndexForward?

withScanIndexForward(Boolean scanIndexForward) Specifies the order for index traversal: If true (default), the traversal is performed in ascending order; if false , the traversal is performed in descending order.

What is Dynamoose?

Dynamoose is a modeling tool for Amazon’s DynamoDB. Dynamoose is heavily inspired by Mongoose, which means if you are coming from Mongoose the syntax will be very familar.

What is PaginatedScanList?

Class PaginatedScanList Implementation of the List interface that represents the results from a scan in AWS DynamoDB. Paginated results are loaded on demand when the user executes an operation that requires them.

What is DynamoDBIndexRangeKey?

Annotation Type DynamoDBIndexRangeKey. @Retention(value=RUNTIME) @Target(value={FIELD,METHOD}) public @interface DynamoDBIndexRangeKey. Annotation for marking a property in a class as the attribute to be used as range key for one or more local secondary indexes on a DynamoDB table.

What is DynamoDBMapperConfig?

public class DynamoDBMapperConfig extends Object. Immutable configuration object for service call behavior. An instance of this configuration is supplied to every DynamoDBMapper at construction; if not provided explicitly, DEFAULT is used.

What is PaginatedQueryList?

Class PaginatedQueryList Implementation of the List interface that represents the results from a query in AWS DynamoDB. Paginated results are loaded on demand when the user executes an operation that requires them.

What is LastEvaluatedKey?

LastEvaluatedKey. The primary key of the item where the operation stopped, inclusive of the previous result set. Use this value to start a new operation, excluding this value in the new request. If LastEvaluatedKey is empty, then the “last page” of results has been processed and there is no more data to be retrieved.

What is Expressionattributevalues?

Expression attribute values in Amazon DynamoDB are substitutes for the actual values that you want to compare—values that you might not know until runtime. An expression attribute value must begin with a colon ( : ) and be followed by one or more alphanumeric characters.

Is Dynamoose good?

Dynamoose is obviously inspired by mongoose and is a good choice if you have a well-defined schema and/or want to be abstracted away from the DynamoDB details. Show activity on this post.

Is DynamoDB like MongoDB?

Both these databases support multi-document transactions, but with key differences: MongoDB supports read and writes to the same documents and fields in a single database transaction. DynamoDB lacks support for multiple operations within a single transaction.

What is Dynamodbhashkey?

Hash key is used to select the DynamoDB partition. Partitions are parts of the table data. Range keys are used to sort the items in the partition, if they exist. So both have a different purpose and together help to do complex query. In the above example hashkey1 can have multiple n-range.

What is DynamoDB pagination?

DynamoDB paginates the results from Query operations. With pagination, the Query results are divided into “pages” of data that are 1 MB in size (or less). An application can process the first page of results, then the second page, and so on. A single Query only returns a result set that fits within the 1 MB size limit.

What is Expressionattributenames?

An expression attribute name is a placeholder that you use in an Amazon DynamoDB expression as an alternative to an actual attribute name. An expression attribute name must begin with a pound sign ( # ), and be followed by one or more alphanumeric characters.

What is Keyconditionexpression in DynamoDB?

This allows Query to retrieve one item with a given partition key value and sort key value, or several items that have the same partition key value but different sort key values. from the docs. It is not supported by DynamoDB and it is actually to save your money.

Is DynamoDB a MongoDB?

For instance, DynamoDB is a managed NoSQL database service, while MongoDB is NoSQL database software. Thus, the nearest direct comparison would be with MongoDB Atlas, the managed database offered by MongoDB Inc and DynamoDB.

Is DynamoDB NoSQL?

Amazon DynamoDB is a fully managed, serverless, key-value NoSQL database designed to run high-performance applications at any scale. DynamoDB offers built-in security, continuous backups, automated multi-Region replication, in-memory caching, and data export tools.

Is DynamoDB a Redis?

DynamoDB intensifies its strength with Amazon DynamoDB Accelerator (DAX) which works just like Redis, but with an in-memory cache for DynamoDB. Primarily, DynamoDB can be comparable with MongoDB which both are sufficiently performant for persistent NoSQL database storage.

What is dynamodbmapper in Java?

Java: DynamoDBMapper. The AWS SDK for Java provides a DynamoDBMapper class, allowing you to map your client-side classes to Amazon DynamoDB tables. To use DynamoDBMapper, you define the relationship between items in a DynamoDB table and their corresponding object instances in your code.

What is the best way to work with DynamoDB data?

DynamoDBMapper offers an intuitive, natural way of working with DynamoDB data within Java. It also provides several built-in features, such as optimistic locking, ACID transactions, autogenerated partition key and sort key values, and object versioning. © 2021, Amazon Web Services, Inc. or its affiliates.

How do I map object fields to DynamoDB attribute names?

This code defines a plain old Java object (POJO) named CatalogItem, which uses annotations to map object fields to DynamoDB attribute names. In the preceding code, the @DynamoDBTable annotation maps the CatalogItem class to the ProductCatalog table. You can store individual class instances as items in the table.

How do I request strongly consistent reads from dynamodbmapper?

You must provide the primary key of the item that you want to retrieve. You can provide optional configuration parameters using the DynamoDBMapperConfig object. For example, you can optionally request strongly consistent reads to ensure that this method retrieves only the latest item values as shown in the following Java statement.