Informix Error -9709: More than one distinct type of the parameter type have cast to argument type.

Reasons / Common Causes

-9709 fires when more than one distinct type of a routine's parameter source type has a cast from the call's argument type — per the official guidance.

1. Multiple distinct types over the same source type, both reachable from the argument type via a cast, per the official guidance — the direct, only cause. For example, routine_name(paramtype) exists; paramdist1 and paramdist2 are both distinct types of paramtype; the call is routine_name(argtype); casts exist from argtype to both paramdist1 and paramdist2. Since distinct types inherit routines defined on their source type, both inherit routine_name, and resolution can't pick one.

Solutions / Resolution

1. Use an explicit CAST on the argument to a specific distinct type, consistent with the official guidance's description of the ambiguity, to disambiguate which inherited routine is called.

Examples

An ambiguous call across distinct types

CREATE DISTINCT TYPE paramdist1 AS paramtype;
CREATE DISTINCT TYPE paramdist2 AS paramtype;
CREATE FUNCTION routine_name(a paramtype) RETURNING INT ...;
SELECT routine_name(some_argtype_value) FROM tab;   -- -9709

Corrected

SELECT routine_name(CAST(some_argtype_value AS paramdist1)) FROM tab;

Diagnostic Checks

1. Check the system catalog for distinct types sharing the same source type as the routine's parameter, and add an explicit cast to pick one.

Related Errors / Related Topics

• -9700 — "Routine (routine_name) ambiguous - more than one routine resolves to given signature." The general routine-ambiguity error this is a specific case of, arising through distinct-type inheritance specifically.

The call was ambiguous across multiple distinct types inheriting the same routine — cast the argument to a specific distinct type.