Application Remote Interface (ARI)


This program shows the performance impact of Application
Remote Interface (ARI), an OS/2 term for Remote Procedure
Call.

The median value is being found for the column C_ENDBAL
from table CHECKING.  The module noari() uses the SQL
queries:


     EXEC SQL SELECT COUNT(*)
         INTO :num_rows
         FROM BMCHUGH.CHECKING;


     EXEC SQL DECLARE CBLOCK CURSOR FOR
        SELECT C_ENDBAL FROM BMCHUGH.CHECKING
        ORDER BY C_ENDBAL;


Then the cursor CBLOCK is used num_rows/2 times to FETCH
the desired median balance.

In the ARI version the module arir() uses the ari call:

      sqleproc("aris.dll\\get_total", NULL, NULL, out_sqlda, &sqlca);

which in turn calls the remote function get_total(), stored
on the server in the DLL aris.dll which is in a subdirectory in
the LIBPATH of the server.

The get_total function carries out the necessary operations
mentioned above and returns the median balance in the data
structure out_sqlda.  Since the operations are performed on
the server only one trip is made between the server and the
requester, with substantial savings in communication cost,
even over record blocking.


CONCEPTS:

Application Remote Interface, sqleproc, SQLDA for ARI, making
DLL's, memory allocation.