EC
1475
MySQLERRORNotableDDLHIGH confidence

Table needs to be rebuilt to enable fast alter

Production Risk

Medium — the ALTER TABLE fails; a rebuild may cause downtime.

What this means

ER_TABLE_NEEDS_REBUILD (1475, SQLSTATE HY000) is returned when a table must be rebuilt before a fast (in-place) ALTER TABLE operation can be performed on it.

Why it happens
  1. 1Table has pending fast alter changes that require a rebuild
  2. 2Old table format incompatible with the requested in-place operation
How to reproduce
trigger — this will error
trigger — this will error
ALTER TABLE my_table ADD COLUMN new_col INT, ALGORITHM=INPLACE;
-- When table needs rebuild first

expected output

ERROR 1475 (HY000): Table definition has changed, please retry transaction

Fix

Rebuild the table first with ALGORITHM=COPY

Rebuild the table first with ALGORITHM=COPY
-- Force a full table rebuild:
ALTER TABLE my_table ENGINE=InnoDB, ALGORITHM=COPY;

-- Then retry the fast alter:
ALTER TABLE my_table ADD COLUMN new_col INT, ALGORITHM=INPLACE;

Why this works

A full rebuild updates the table format to the current version, enabling subsequent in-place operations.

Sources
Official documentation ↗

MySQL 8.0 — 1475 ER_TABLE_NEEDS_REBUILD

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