Hello

As I use Sierra Chart, it seems to accumulate datas every single day. Now it got very large at 7gb.

What is the proper way of cleaning this? Should I just go to data folder and delete SCID files?

I sounds as if you are collecting high resolution tick data -
you can set this to 1-minute - if you dont need tick data history.

Also, I think one can force Sierra to automatically export big data junks to an external drive.

Have a look at the sierra support website for this.

About scid-files:

Yes - they store the intraday data in sierra.
EoD data is stored in .dly files.

If you dont need (long) intraday history - you can delete the scid-files.
But read the Sierra documentation first.

puma is correct -- you can delete the files you don't need. For compressing the data, you can go to File->Data/Trade Service Settings->Data File Management