Re: support ALTER TABLE DROP EXPRESSION for virtual generated column

2025-07-13 Thread David G. Johnston
On Wed, Mar 26, 2025 at 8:15 PM Tom Lane wrote: > jian he writes: > > the attached patch is to implement $subject. > > Why would this be a good idea? I don't see any principled fallback > definition of the column. (No, "NULL" is not that.) Certainly we > should support ALTER TABLE DROP COLUMN

Re: support ALTER TABLE DROP EXPRESSION for virtual generated column

2025-03-29 Thread jian he
On Thu, Mar 27, 2025 at 11:44 AM David G. Johnston wrote: > > On Wednesday, March 26, 2025, Tom Lane wrote: >> >> jian he writes: >> > the attached patch is to implement $subject. >> >> Why would this be a good idea? I don't see any principled fallback >> definition of the column. (No, "NULL"

Re: support ALTER TABLE DROP EXPRESSION for virtual generated column

2025-03-26 Thread Tom Lane
jian he writes: > the attached patch is to implement $subject. Why would this be a good idea? I don't see any principled fallback definition of the column. (No, "NULL" is not that.) Certainly we should support ALTER TABLE DROP COLUMN, but removing the expression and not providing a substitute

Re: support ALTER TABLE DROP EXPRESSION for virtual generated column

2025-03-26 Thread David G. Johnston
On Wednesday, March 26, 2025, Tom Lane wrote: > jian he writes: > > the attached patch is to implement $subject. > > Why would this be a good idea? I don't see any principled fallback > definition of the column. (No, "NULL" is not that.) Certainly we > should support ALTER TABLE DROP COLUMN,