The following bug has been logged on the website:
Bug reference: 17360
Logged by: Gergely Czuczy
Email address: gergely.czuczy@harmless.hu
PostgreSQL version: 13.3
Operating system: FreeBSD13
Description:
Hello,
The array_to_string function should have a volatility of immutable, it
perfectly fits the requirements in the documentation.
Where this comes to play is generated columns, when one wishes to have a
field something like GENERATED ALWAYS AS (array_to_string(ARRAY[selector,
'_domainkey', subdomain], '.')) STORED.
Reading the documentation I haven't found anything that would prevent the
function from being immutable, and enable this kind of usecases.
Best regards,
Gergely