Some data rows can be very large; for example, in a MS SQL Server database, rows often have large fields such as IMAGE and MEMO. The ODBC protocol specifies a dynamic buffer allocation process for handling large rows that do not initially fit into clients' buffers; however, some drivers do not yet follow the correct ODBC protocol and do not handle these large rows correctly. Use the -Dsrv PRGRS_MINBUF,size option to force a minimum buffer size. For example, -Dsrv PRGRS_MINBUF,15000 enables the DataServer to handle 15K rows even with drivers that fail to follow the ODBC protocol.

The optimal setting for PRGRS_MINBUF is the size of the largest record data size plus 500 bytes. This can prevent run-time record expansion during the retrieval of query results.

Do not use this option when the -Dsrv BINDING switch is set to 3. With the binding set to 3, the size of the data is known, and this switch will cause the allocation of unneeded additional memory.

It is often difficult to determine when there is a buffer size problem and how to choose the correct value for PRGRS_MINBUF. Be careful when using this option.