Can i improve the performance of my MT4/5 terminal if i delete periodically the journal log files? Any other files we should delete periodically?

 
hi i wander apart from the journal log files what other files we should delete periodically so as the performance of old Mt5/4 installations gets improved? If too much history files sometimes they get slower
 

if your terminal has issues, then, imo it is faster less troublesome to simply delete or uninstall mt4/5 and then to install it again. Just remember to backup your user files before you do uninstall it.

and periodicly backup your custom indicators and eas. so that when your terminal does have issues, you always have a backup to fall back on.

NOTE : I use the mt4/5 feature "portable". I have a backup of a clean mt4/5 so that when my terminal does break or has issues, I just delete the offending terminal and then make a new copy of the clean one, that already has my custom files installed. Just remember that this may use an activation when you start up the clean terminal, however, it might not.
 
Log files are named by date. Deleting old ones will save you disk space, nothing more.