Unavoidable query failure on results containing arrays of multirange values

[nikita-volkov]

postgresql-simple attempts to query the pg_range system catalog to determine the element subtype, as it treats multirange types as range-like types. However, multirange types (introduced in PostgreSQL 14) are not stored in pg_range, causing the query to fail with range subtype query failed to return exactly one result. This seems impossible to circumvent even with custom types, because the error is triggerred by PGArray.

[phadej]

Please include steps to reproduce

[nikita-volkov]

Check out https://github.com/nikita-volkov/postgresql-simple-postgresql-types/tree/149581fdbd82d7cfc2aa11e0e52db5ef68c93d5d and run the tests.

[phadej]

If you don't care to minimize the reproducer (so eventually something like that could be added to postgresql-simple's own test-suite), I probably won't care to look into this issue either.

[nikita-volkov]

Ok. Was just trying to help.

[phadej]

@nikita-volkov No worries. If someone runs into this issue, and needs it to be fixed, they might provide a reproducer.

I'm not using multirange types anywhere myself, so my intrinsic motivation to look into this is quite low.