Andres Freund <andres@anarazel.de> writes:
> On 2022-11-29 00:24:49 +0300, Nikita Malakhov wrote:
>> 2) Upgrading to 64-bit id would require re-toasting old TOAST tables. Or
>> there is some way to distinguish old tables from new ones?
> The catalog / relcache entry should suffice to differentiate between the two.
Yeah, you could easily look at the datatype of the first attribute
(in either the TOAST table or its index) to determine what to do.
As I said before, I think there's a decent argument that some people
will want the option to stay with 4-byte TOAST OIDs indefinitely,
at least for smaller tables. So even without the fact that forced
conversions would be horridly expensive, we'll need to continue
support for both forms of TOAST table.
regards, tom lane