Optimizing Iceberg tables
Amazon Glue supports mutiple table optimization options to enhance the management and performance of Apache Iceberg tables used by the Amazon analytical engines and ETL jobs. These optimizers provide efficient storage utilization, improved query performance, and effective data management. There are three types of table optimizers available in Amazon Glue:
Compaction – Data compaction compacts small data files to reduce storage usage and improve read performance. Data files are merged and rewritten to remove obsolete data and consolidate fragmented data into larger, more efficient files. Compaction can be configured to run automatically or manually triggered as needed.
Snapshot retention – Snapshots are timestamped versions of an Iceberg table. Snapshot retention configurations allow customers to enforce how long to retain snapshots and how many snapshots to retain. Configuring a snapshot retention optimizer can help manage storage overhead by removing older, unnecessary snapshots and their associated underlying files.
Orphan file deletion – Orphan files are files that are no longer referenced by the Iceberg table metadata. These files can accumulate over time, especially after operations like table deletions or failed ETL jobs. Enabling orphan file deletion allows Amazon Glue to periodically identify and remove these unnecessary files, freeing up storage.
You can enable or disable compaction, snapshot retention, and orphan file deletion optimizers for individual Iceberg tables in the Data Catalog using the Amazon Glue console, Amazon CLI, or Amazon Glue API operations.