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Thread: Note that ALTER TABLE cannot alter generated stored columns

Note that ALTER TABLE cannot alter generated stored columns

From
Emre Hasegeli
Date:
I was trying to change the generation expression of a generated stored
column using ALTER TABLE.  It took me a while before I figured SET
GENERATED applies only to generated identity columns.  I think it'd be
useful to note this in the documentation with something like the
attached.
Attachment

Re: Note that ALTER TABLE cannot alter generated stored columns

From
Laurenz Albe
Date:
On Sun, 2021-05-30 at 16:25 +0300, Emre Hasegeli wrote:
> I was trying to change the generation expression of a generated stored
> column using ALTER TABLE.  It took me a while before I figured SET
> GENERATED applies only to generated identity columns.  I think it'd be
> useful to note this in the documentation with something like the
> attached.

+1

Yours,
Laurenz Albe

Re: Note that ALTER TABLE cannot alter generated stored columns

From
Peter Eisentraut
Date:
On 30.05.21 15:25, Emre Hasegeli wrote:
> I was trying to change the generation expression of a generated stored
> column using ALTER TABLE.  It took me a while before I figured SET
> GENERATED applies only to generated identity columns.  I think it'd be
> useful to note this in the documentation with something like the
> attached.

I don't follow why you put this documentation under ALTER TABLE ... DROP 
EXPRESSION.  That action doesn't seem related to what you were hoping to do.

Re: Note that ALTER TABLE cannot alter generated stored columns

From
Emre Hasegeli
Date:
> I don't follow why you put this documentation under ALTER TABLE ... DROP
> EXPRESSION.  That action doesn't seem related to what you were hoping to do.

I thought that's where it would be if we had ADD/SET EXPRESSION
statements, just like the ADD/SET GENERATED statements just below.