stat/compression is a SAP Parameter attribute which is used to control compress statistic records information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This parameter defines whether the statistics records are to be
compressed for storage in the statistics file. This allows you to reduce
the space required for the statistics file. However, this is at the
expense of CPU requirements.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.