RS-LOCK-001 — ACCESS EXCLUSIVE lock for a full table rewrite
Namespace: RS-LOCK · Code: RS-LOCK-001
Adding a column with a volatile default, or changing a column’s type, rewrites every row while holding an ACCESS EXCLUSIVE lock — no reads or writes proceed until it finishes. On a large table that is a write outage.
Remediation
Section titled “Remediation”Avoid the full-table ACCESS EXCLUSIVE rewrite. For a volatile default: ADD the column nullable with no default, backfill in batches, then attach the default and SET NOT NULL via a validated CHECK. For a type change: add a new column of the target type, backfill it in batches, swap reads/writes, and drop the old column. Each step is online.
References
Section titled “References”- RFC §9.1
- PRD §10
This page is generated from the same catalog rowshape explain RS-LOCK-001 reads, so the remediation here is byte-identical to the one a verdict carries — they cannot drift. An agent can read it with the explain_finding MCP tool.