stat/trexrec is a SAP Parameter attribute which is used to control Max. number of trex subrecords for one statistic record 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 .
The number of Trex statistics can be defined in the SP Kernel/Statistic
using the parameter stat/trexrec.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.