Re: Move pg_attribute.attcompression to earlier in struct for reduced size?

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Wed, May 26, 2021 at 11:13 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> * As things stand here, once you've applied ALTER ... SET COMPRESSION
>> to select a specific method, there is no way to undo that and go
>> back to the use-the-default setting. All you can do is change to
>> explicitly select the other method. Should we invent "ALTER ...
>> SET COMPRESSION default" or the like to cover that?

> Yes. Irreversible catalog changes are bad.

Here's an add-on 0004 that does that, and takes care of assorted
silliness in the grammar and docs --- did you know that this patch
caused
alter table foo alter column bar set ;
to be allowed?

I think this is about ready to commit now (though I didn't yet nuke
GetDefaultToastCompression).

regards, tom lane