Postgres Pro
Downloads
Home   >   mailing lists

Re: v18 virtual columns - Mailing list pgsql-general

From Dominique Devienne
Subject Re: v18 virtual columns
Date
Msg-id CAFCRh--3iD9sSwakKvm9-Od+0RBEuLGy35dD72C5G9PzCYEiTg@mail.gmail.com
Whole thread Raw
In response to Re: v18 virtual columns  (Ron Johnson <ronljohnsonjr@gmail.com>)
List pgsql-general
Tree view
On Thu, Feb 20, 2025 at 3:31 PM Ron Johnson <ronljohnsonjr@gmail.com> wrote:
On Thu, Feb 20, 2025 at 8:07 AM Dominique Devienne <ddevienne@gmail.com> wrote:
Hi. I've just read https://www.dbi-services.com/blog/postgresql-18-virtual-generated-columns/

and I'm wondering whether there will be a way to ALTER existing STORED generated columns, to be virtual? W/o rewriting the whole table that is.

What about dropping the existing stored column then adding the new virtual column?

You won't get any disk space saving for existing records, but it's not going to rewrite the table.

Didn't think of that, but yes, I think that would work.
They are GENERATED columns, so the values stored are derived data anyway, indeed.

I also didn't know DROP COLUMN was smart enough not rewriting the column, that's good.

Thanks, --DD

pgsql-general by date:

Previous
From: Dominique Devienne
Date:
Subject: #XX000: ERROR: tuple concurrently updated
Next
From: Tom Lane
Date:
Subject: Re: #XX000: ERROR: tuple concurrently updated