How to prevent data loss by backfill?

When I use IB data, the stock data always backfill and delete the old data

Is there any database setting can prevent "backfill" delete the old data?
This is my database setting

OR

I would like to save the data to another name,
such as AVGO-SMART_STK_USD , I want to auto save the data to "AVGO-Histo"

Can I make it by several click, choosing
Symbol -> Merge -> Destination : "AVGO-Histo" , Merge with : AVGO-SMART_STK_USD
tick the box " Assign an alias name "

Thanks!

Data are NOT lost by backfill.

New data are appended for as long as you have specified in File->Database Settings, "Number of bars". If you have 20000 bars entered there, upto 20000 bars will be kept. If you want more to keep, increase the value. It is up to you.

This of course assumes that you have properly purchased license and activated software.

thanks, Tomasz
I have purchased the license and activate the software properly and used for few years aly.

Data disappear whenever backfill is always happen i set 15days backfill length, then after backfill, sometimes only new 15days data left.

Is it old version problems and aly fixed at new version?

No, it does NOT disappear. And nothing is needed except configuring the plugin precisely as it is shown in the manual. Base time interval should be ONE MINUTE, not 15 minutes, and number of bars should be set to the proper amount.

See: On-line Data size calculator