Eg. If I replace my wallet.dat on 23/8/2017, and I put it back on 27/8/2017, the client will rescan the wallet from 23/8/2017.
This is not a problem.
Instead of renaming wallet.dat, use this option when you start Bitcoin Core:
-wallet=
Specify wallet file (within data directory) (default: wallet.dat)
Update: tested the prune version , and works perfectly.
But tested the changing the wallet.dat files. It works also perfectly, only at startup will rescan from the last seen block(can be 100....also). So look like the wallet.dat save the last checked block, and rescan from that one.
In my case, to save space, prune=10000, and changing the wallets in regular base.
Thanks again for all advise!
This can be a problem if you keep a wallet offline for longer than your prune allows.