Function calcArrayOid

postgres/parser/types/oid.go:208–241

calcArrayOid returns the OID of the array type having elements of the given type.

(elemTyp *T)

// calcArrayOid returns the OID of the array type having elements of the given
// type.
func calcArrayOid(elemTyp *T) oid.Oid {
	o := elemTyp.Oid()
	switch elemTyp.Family() {
	case ArrayFamily:
		// Postgres nested arrays return the OID of the nested array (i.e. the
		// OID doesn't change no matter how many levels of nesting there are),
		// except in the special-case of the vector types.
		switch o {
		case oid.T_int2vector, oid.T_oidvector:
			// Vector types have their own array OID types.
		default:
			return o
		}

	case UnknownFamily:
		// Postgres doesn't have an OID for an array of unknown values, since
		// it's not possible to create that in Postgres. But CRDB does allow that,
		// so return 0 for that case (since there's no T__unknown). This is what
		// previous versions of CRDB returned for this case.
		return unknownArrayOid

	case EnumFamily:
		return elemTyp.UserDefinedArrayOID()
	}

	// Map the OID of the array element type to the corresponding array OID.
	// This should always be possible for all other OIDs (checked in oid.go
	// init method).
	o = oidToArrayOid[o]
	if o == 0 {
		panic(errors.AssertionFailedf("oid %d couldn't be mapped to array oid", o))
	}
	return o
}