Operating system and syntax UNIX Windows -Mm n
Use with Maximum value Minimum value Single-user default Multi-user default
CC, DBS 32,600 350 — 8192
n
The message buffer size.

Use Message Buffer Size (-Mm) to specify the standard message buffer size, in bytes. This parameter is relevant only for network client/server connections. Message Buffer Size (-Mm) can be specified by both the client and the server, however the size of the message buffer specified by the server takes precedence; a value specified by the client is used as a suggestion for initial buffer allocation, but the client then adopts the server value when the connection is initiated.

OpenEdge uses message buffers to move records (messages) between servers and remote clients. Records (plus 40-byte headers) larger than the message buffer size are fragmented into multiple messages. If your database records are large, increase this parameter to avoid record fragmentation. However, if the network works more efficiently with small messages, reduce -Mm and fragment larger records.

To change this parameter while the database is running, use PROMON or the _DbParams VST.

You can use this parameter to support continuous operation of the database. For more information, see Change database parameters while the database is running.