Re: ALTER COLUMN ... SET EXPRESSION to alter stored generated column's expression

On 28.08.23 11:54, Amul Sul wrote:
> Thanks for the review comments, I have fixed those in the attached
> version. In
> addition to that, extended syntax to have the STORE keyword as suggested by
> Vik.

An additional comment: When you change the generation expression, you
need to run ON UPDATE triggers on all rows, if there are any triggers
defined.  That is because someone could have triggers defined on the
column to either check for valid values or propagate values somewhere
else, and if the expression changes, that is kind of like an UPDATE.

Similarly, I think we should consider how logical decoding should handle
this operation.  I'd imagine it should generate UPDATE events on all
rows.  A test case in test_decoding would be useful.