This is the setting I use for solving problems with barrier, no presolve, no crossover.
Hope it can be useful.
CPXENV = CPLEX.Env() # create CPLEX environment
# Set parameters
CPLEX.set_param!(CPXENV, "CPXPARAM_ScreenOutput", 1) # Enable output
CPLEX.set_param!(CPXENV, "CPXPARAM_TimeLimit", 3600) # Time limit
CPLEX.set_param!(CPXENV, "CPXPARAM_Threads", 1) # Single thread
CPLEX.set_param!(CPXENV, "CPXPARAM_SolutionType", 2) # No crossover
CPLEX.set_param!(CPXENV, "CPXPARAM_LPMethod", 4) # Use barrier
CPLEX.set_param!(CPXENV, "CPXPARAM_Preprocessing_Presolve", 0) # No presolve
...
CPLEX should display non-default parameters values at the beginning of the optimization.
For the above case, you should see something like this in the log:
...
CPXPARAM_Preprocessing_Presolve 0
CPXPARAM_LPMethod 4
CPXPARAM_Threads 1
CPXPARAM_SolutionType 2
CPXPARAM_TimeLimit 3600
...
FWIW, I’ve observed that CPLEX still performs a “reduced presolve”, even with the CPXPARAM_Preprocessing_Presolve set to 0.
As odow points out, the answer to all these questions will be in CPLEX’s documentation, there’s nothing additional that’s done in the Julia wrapper.