MySQL Bugs: #120237: DEFAULT(UUID()) allowed at CREATE TABLE but rejected in ALTER TABLE with binary logging enabled

Bug #120237	DEFAULT(UUID()) allowed at CREATE TABLE but rejected in ALTER TABLE with binary logging enabled
Submitted:	8 Apr 17:05	Modified:	9 Apr 8:59
Reporter:	João Martins	Email Updates:
Status:	Documenting	Impact on me:	None
Category:	MySQL Server: DDL	Severity:	S3 (Non-critical)
Version:	9.6 and 8.4	OS:	Any
Assigned to:		CPU Architecture:	Any

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Description:
Non‑deterministic DEFAULT expressions (e.g. UUID()) are accepted when defined at CREATE TABLE time, but rejected when the same DEFAULT is added via ALTER TABLE, even when binary logging is enabled in ROW mode.

This behaviour might be intentional (for replication safety?), but I did not found explicitly documented it can also be a bug.

How to repeat:
CREATE TABLE t1 (
    i INT,
    b BINARY(16) DEFAULT (UUID_TO_BIN(UUID()))-- This succeeds
);

ALTER TABLE t1
ADD COLUMN c BINARY(16)
DEFAULT (UUID_TO_BIN(UUID(), 1)); -- This fails with: ERROR 1674 (HY000)

Posted by developer: Bug status updated to 'Documenting'