Query Interface

Custom API Command-line / Shell

Users can query the database via a CLI or SDKs.

Storage Model

Custom

Storage Architecture

Hybrid

DynamoDB supports a pluggable local persistence engine that can range from in-memory buffers with persistent backing to purely disk-oriented ones. This allows it to be flexible with an application's access patterns.

Joins

Not Supported

DynamoDB does not support joins natively as it is a key-value store and not a relational database. However, Amazon's EMR service supports joining DynamoDB tables.

Logging

Not Supported

Although there are no implementation details on DynamoDB's internal logging schema, users can log DynamoDB API operations via AWS CloudTrail.

Concurrency Control

Optimistic Concurrency Control (OCC)

Users have the ability to enable Optimistic Locking for DynamoDB using the AWS Java SDK.

Data Model

Key/Value Document / XML

DynamoDB is schemaless. Each table requires a primary key to identify its corresponding data item. However, there are no such constraints on non-key attributes.

DynamoDB can hold both structured or semi-structured data, such as JSON or XML.

Query Compilation

Not Supported

Isolation Levels

Read Uncommitted Read Committed Repeatable Read

DynamoDB has three configurable isolation levels: Read Uncommitted, Read Committed, and Repeatable Reads.

Views

Materialized Views

DynamoDB Streams can create materialized views of data in DynamoDB tables.

Compression

Bit Packing / Mostly Encoding

While DynamoDB doesn't natively support compression, users can compress large attributes into binary data using compression algorithms like LZO or GZIP.

Stored Procedures

Not Supported

Although DynamoDB doesn't natively support stored procedures, users can use AWS Lambdas for a similar effect.

System Architecture

Shared-Nothing

Nodes are partitioned via consistent hashing, and utilize gossip-based membership protocol.