AWS Glue vs Delta Lake: What are the differences?

Introduction

This Markdown code highlights the key differences between AWS Glue and Delta Lake.

1. Data Storage: AWS Glue is a fully managed extract, transform, and load (ETL) service that allows you to prepare and transform massive amounts of data for analytics. It does not provide storage capabilities but integrates with various data storage services like Amazon S3 and Amazon Redshift. On the other hand, Delta Lake is an open-source data lake storage layer that adds reliability, scalability, and performance optimizations to cloud storage systems such as S3 and Azure Data Lake Storage Gen1/Gen2.

2. ACID Transactions: Delta Lake provides support for ACID (Atomicity, Consistency, Isolation, Durability) transactions, ensuring that data modifications follow these properties. It allows for concurrent reads and writes, enables accurate rollbacks, and provides transactional consistency. AWS Glue, on the other hand, does not provide built-in ACID transactions, and data modifications may not be atomic or consistent.

3. Schema Evolution: Delta Lake supports schema evolution, which allows changes to the structure of the data over time. It handles schema changes seamlessly and provides flexibility in evolving data models. AWS Glue, however, does not have direct support for schema evolution and may require manual intervention or additional processing to handle schema changes.

4. Data Validation: Delta Lake includes a mechanism for data validation using schema enforcement. It ensures that data adheres to a predefined schema and rejects writes that violate the schema. This helps maintain data integrity and prevents data corruption. AWS Glue, on the other hand, does not have built-in data validation mechanisms and may require additional data quality checks to ensure data integrity.

5. Metadata Management: AWS Glue provides a metadata catalog that allows you to define, manage, and discover metadata for various data sources, including tables, databases, and jobs. It provides a centralized view of metadata and fosters data governance. Delta Lake, while not specifically offering a metadata management system, allows storing metadata in its transactional log to track changes in tables and data.

6. Data Lake Optimization: Delta Lake provides various optimizations for data lake workloads, including indexing, data skipping, and Z-ordering. These optimizations improve query performance by reducing data IO and promoting query pushdown to the storage layer. AWS Glue, being an ETL service, focuses more on data transformation and preparation rather than optimizing data lake workloads.

In summary, AWS Glue is a fully managed ETL service that integrates with storage services, while Delta Lake is an open-source data lake storage layer that adds reliability, scalability, and transactional capabilities to cloud storage systems. Delta Lake provides support for ACID transactions, schema evolution, data validation, and data lake optimizations, whereas AWS Glue focuses on ETL operations and metadata management without ACID transactions or built-in schema evolution capabilities.