Exam Guide: Developer - Associate 🏗️ Domain 1: Development with AWS Services 📘 Task 3: Use Data Stores In Application Development DynamoDB dominates this task. The need to understand table design, key selection, indexing, consistency models, and how to write efficient queries is essential. As well as caching with ElastiCache and DAX. Plus specialized stores like OpenSearch. 📘 Concepts DynamoDB Key Concepts Primary Keys Every table needs one. Two options: Simple primary key: Partition key only (PK). Each item has a unique PK. Composite primary key: Partition key (PK) + Sort key (SK). Multiple items can share a PK if they have different SKs. Partition Key Selection The partition key determines which physical partition stores your data. A good partition key has high cardinality which refers to many distinct values so that the data spreads evenly.…