Issues that R-SIG-DB hasn't resolved.

1. Should we define separate classes for SQL queries that return data
   from those that don't return data?  E.g., the "DBIResult"
   could represent the result of non-data queries (INSERT, DELETE,
   CREATE, etc.) while "DBIResultSet" (or perhaps "DBICursor")
   could extend "DBIResult" to represent results of queries that
   generate data (primarily SELECT).

2. Data conversion.  We need a general method for spcifying data 
   conversion.  

   The data conversion mechanism used in other inter system packages
   (e.g., RSPython, RSPerl) does not seem to be suitable without
   modification.  Those mechanism seem to be geared for converting
   in one operation whole objects, while in the R/S DBMS case we
   need to be able to allocate containers as columns of the R/S
   result list/data.frame, and then transfer individual objects
   (dates, BLOBS, CLOBS, numerbs, strings) one at a time from the
   DBMS into the container class inside the C fetching looping.
     
3. Other metadata? (e.g., table indices).

4. Transaction management needs to be fully described.

5. How do we run SQL scripts (not just single statements) and
   stored procedures.

6. "Bind" variables".

7. Asynchronous queries.

