EMA C++ Performace Tools Guide : 10 Performance Best Practices : 10.2 Enterprise Message API Best Practices : 10.2.7 Compression
 
10.2.7 Compression
The Enterprise Message API supports the use of data compression. Generally, compressing data reduces the amount of data passed to the underlying transport. But compression has some drawbacks to consider:
Compression requires additional processing.1
Compression copies data: as the user-provided buffer is read by the compression algorithm, output data is compressed into a different buffer. As a result, compression will generally require more buffers from the Enterprise Message API’s buffer pool.
 

1 Overhead will vary based on the type of compression used and the level of compression applied.