Partition Projection
See how Athena computes partition locations from rules, why registration is ignored, and how an incorrect range can silently hide existing data.
-
-
Partition Pruning
Use partition values to exclude locations, distinguish pruning from row filtering, and avoid changing the answer just to reduce scanning.
-
External Table
Understand how an external table maps SQL to stored data, what registration controls, and why visibility alone is not a committed snapshot.
-
External Tables and the Lake/Warehouse Boundary
An external table exposes files to SQL. Learn when to load a managed copy and how registration, updates, and snapshots affect correctness.