EMA C++ RDM Usage Guide : 8 Market By Price Domain : 8.3 Data
 
8.3 Data
8.3.1 Response Message Payload
The payload is a Map. Refreshes for this Map may be in multiple Response messages. The bandwidth of the refresh messages can be optimized by putting multiple MapEntry in each response message. For optimal performance the packed map entries in each response message should use less than 6000 bytes. If the data is split into multiple messages, then a Map.TotalCountHint should be provided to optimize downstream caching. Since the fields in each map entry are the same, bandwidth can be further optimized by DataDefinitions.
Figure 15. MarketByPrice Response Message Payload