Tag
ddl
- Oct 8, 2025 Which ALTER TABLE Statements Rewrite the Table and Which Only Touch the Catalogue How engines decide between a catalogue edit and a full table copy, what the fast-default and instant-column mechanisms store instead, and where the boundary sits. databases
- Feb 13, 2025 Concurrent Index Builds and the Invalid Index They Can Leave Behind Why a non-blocking index build performs two scans, what state it commits between them, and how a failure leaves an index that exists but cannot be used. databases
- Mar 12, 2024 Expand and Contract: Changing a Column While Both Versions Run The four-step sequence that lets old and new application code share one schema, which intermediate states must be safe, and where the sequence breaks down. databases
- Apr 11, 2023 How Metadata Locks Block a DDL Statement Behind Ordinary Queries The lock queue that a schema change must pass through, why a short query in front of it can stall every new reader of the table, and the timeout that bounds the damage. databases