SQLite Forum

IS NULL optimization on NOT NULL constraints breaks on corrupted databases
> \[Regarding effects of changing sqlite_schema table via UPDATE\] ...<br>
Which isn't obvious, and a change of behavior with respect to older SQLite versions

The effect of making your own changes to the schema table is undocumented and undefined, and always has been. Changes in undocumented behavior are sometimes intentionally avoided as the project evolves, but not always and not in any way that users should rely upon.

Your effort to inform about this particular change of behavior is appreciated. You may consider it a warning about reliance upon undocumented behavior.