How to Add a Column to a Ten‑Million‑Row MySQL Table Without Locking It

When a core MySQL order table reaches tens of millions of rows, adding a new column can lock the table and disrupt services, so the article walks through master‑slave switching, online DDL tools, log‑based workarounds, extension tables, JSON fields, and a final redundant‑field trick to achieve the change safely.

DDL lockJSON columnMySQL

0 likes · 7 min read

How to Add a Column to a Ten‑Million‑Row MySQL Table Without Locking It