PolarDB-X Online DDL — Safe DDL Assessment & Lock-Free Execution

Assess whether DDL operations lock the table and execute them safely on PolarDB-X 2.0 Enterprise Edition (AUTO mode). This skill covers the complete DDL safety workflow: assessment → lock-free rewriting → long transaction checks → user confirmation → execution.

Scope: PolarDB-X 2.0 Enterprise Edition + AUTO mode database only.

Version requirement: Instance version >= 5.4.20-20241224 for EXPLAIN ONLINE_DDL and OMC support. For older versions, see reference guide for legacy compatibility methods.

Core Workflow (Follow each time)

Important: DDL is a high-risk operation. NEVER execute DDL directly without presenting assessment results and obtaining explicit user confirmation.

1. Assess table-locking risk with EXPLAIN ONLINE_DDL:

   EXPLAIN ONLINE_DDL ALTER TABLE ...;
   

   Check the DDL TYPE in the result.