Question

A company is migrating a 12 TB on-premises PostgreSQL database to Amazon Aurora PostgreSQL using AWS DMS. The source contains several very large tables with columns storing multi-megabyte binary documents (BYTEA / LOB data). The initial full-load task is running extremely slowly and occasionally fails, and the team observes that the LOB-heavy tables are the primary bottleneck. Downtime must be minimized, and the migration must complete reliably. Which approach BEST improves full-load performance and reliability for this workload?

Accepted Answer

Enable DMS limited LOB mode with an appropriately sized max LOB size, split the migration into multiple parallel task threads per table using table-level parallel-load settings, and separate the largest LOB tables into their own DMS tasks.

Answer

Switch the DMS task to full LOB mode with an unlimited LOB size and increase the replication instance to the largest available size to guarantee all LOB data transfers in a single pass.

Answer

Disable LOB migration entirely on the DMS task and use AWS DataSync to copy the binary documents separately after the relational data completes.

Answer

Use AWS Snowball Edge to export the entire database as flat files, then bulk-load into Aurora using pg_restore, bypassing DMS for the LOB tables.