add more language

Author: paleolimbot

c/include/arrow-adbc/adbc.h

@@ -1255,6 +1255,10 @@ struct ADBC_EXPORT AdbcDriver {
   AdbcStatusCode (*StatementSetOptionInt)(struct AdbcStatement*, const char*, int64_t,
                                           struct AdbcError*);
 
+  // ADBC 1.2
+  AdbcStatusCode (*StatementRequestSchema)(struct AdbcStatement*, struct ArrowSchema*,
+                                           struct AdbcError*);
+
   /// @}
 
   /// \defgroup adbc-1.2.0 ADBC API Revision 1.2.0
@@ -2305,6 +2309,14 @@ AdbcStatusCode AdbcStatementExecuteSchema(struct AdbcStatement* statement,
 /// AdbcStatementExecuteSchema to request specific Arrow type
 /// variants such as string views or list views.
 ///
+/// The provided schema is a request and not a guarantee (i.e.,
+/// callers must use the schema provided by the output stream to
+/// interpret the result).
+///
+/// Calling AdbcStatementRequestSchema() must not affect the result
+/// of AdbcStatementExecuteSchema (which always infers its result
+/// from the input query).
+///
 /// \since ADBC API revision 1.2.0
 ///
 /// \param[in] statement The statement to execute.