ORA-02070: Error when updating an informix table through orcl view using HS

Question

Hello!
I faced the following problem:
I have a table in informix, and i want to reach this table through Oracle infromix gateway (Heterogenous Services). I succeeded to set up the gateway, and I created an Oracle view for my table in informix. It is working fine, I can query and modify data, except the following case: If I run the query (from SQL Developer) "UPDATE oracle_view SET float_field = '1.1' WHERE record_id = 1 AND float_field = '1.2'", I receive the following error:
"SQL Error: ORA-02070: database database_link does not support TO_NUMBER in this context.
*Cause: The remote database does not support the named capability in the context in which it is used.
*Action: Simplify the SQL statement."
If I modify the query as "UPDATE oracle_view SET float_field = '1.1' WHERE record_id = 1", it is running without any error messages. I found, that to_number is not supported by Oracle HS gateway, but I do not use explicitly the to_number Oracle function! But I must use the above version, because of concurrent users.
Does anybody have an idea how I could get rid of the implicit call of to_number?
Thanks, Gyula

Answer 1

user11229789 wrote:
Yes, float_field is a numeric-type field, which is a 8-byte FLOAT in informix. This field gets automatically FLOAT datatype in the Oracle view, and can not be modified. record_id is some integer unique id field.Well, as the float_field is numeric it makes sense that the SQL issued from Oracle treats it as numeric, so leaving out the quotes can only be the correct thing to do. If you introduce quotes then you are providing strings and the HS is having to do a convertion to numeric (hence where the TO_NUMBER would have been coming into the initial issue.
If I try the update query without '-s you suggested, like this: "UPDATE oracle_view SET float_field = 1.1 WHERE record_id = 1 AND float_field = 1.2" , i receive the following error message:
SQL Error: ORA-28534: "Heterogeneous Services preprocessing error"
*Cause:    One of the things that the Heterogeneous Services can do is
to preprocess parts of SQL statements that contain implicit
coercions or calls to explicit coercion functions like TO_CHAR
TO_NUMBER or TO_DATE. For example, it could convert a call to
TO_DATE to a bind variable, pre-evaluate the TO_DATE function
call and pass the resulting value to the non-Oracle system as
the bind value. This behavior is controlled by some coercion
related capabilities. If the capabilities are set incorrectly,
the HS could encounter errors when it attempts to do the
preprocessing. If it does then this error will be signaled.
*Action:   The capability table settings are controlled by the agent
vendor and can be modified by the DBA. Contact your DBA and
agent vendor and get the correct set of capabilities installed.I can't see why the HS would be trying to do any coercion of anything except to perhaps convert the parts of the where clause to bind variables and pass the actual values in. Does it work ok without the "AND float_field = 1.2" ? If so, I'm guessing there's some configuration issue of the HS required to get it to deal with the floats.... perhaps in the capability settings as the error message "action" indicates.