Tyler Brock <tyler.br...@gmail.com> writes: > I am writing a program that behaves like a Postgres backend and can see > that if I select oid from pg_type that the type old’s could be returned in > the Row Description message for the field’s data type and that seems to > work. > However, I didn’t read anywhere that these are guaranteed to be > constant/stable so I’d like to know if this is the case. For example: is > the old for pg_type bool = 16 on every instance of Postgres?
Hand-assigned OIDs (those below 10000) are stable in released versions. Those above 10K might vary across installations or PG versions. You might find it interesting to read https://www.postgresql.org/docs/current/system-catalog-initial-data.html#SYSTEM-CATALOG-OID-ASSIGNMENT > Also does there exist any documentation decoding what the pg_type fields > all mean? https://www.postgresql.org/docs/current/catalog-pg-type.html regards, tom lane
