MySQL-specific syntax like:
UPDATE users u JOIN orders o ON u.id = o.user_id SET u.status = 'vip' WHERE o.total > 1000
where users and orders are on different backends.
Requires: execute JOIN locally, extract affected PKs, generate per-backend UPDATE WHERE pk IN (...).
Lower priority — the common case (DML with subquery in WHERE) is handled by cross-shard subquery materialization.
MySQL-specific syntax like:
where users and orders are on different backends.
Requires: execute JOIN locally, extract affected PKs, generate per-backend UPDATE WHERE pk IN (...).
Lower priority — the common case (DML with subquery in WHERE) is handled by cross-shard subquery materialization.