Wallet.dat

[niceman]

It's possible to purge some way wallet.dat file size?
I have a pool and my wallet.dat became about 2Mb in one week. I think it's because it saves all transaction's history.
And I have very small pool. I afraid it can grow much faster later.

It's possible to backup only keys for addresses where is some coins and don't backup total transaction's history and all used before, but useless already keys.
It's possible to check what keys stored in wallet.dat has some amount and what is useless?

[deepceleron]

Bitcoin has it's own record of all transactions you have made in your wallet.dat; if it didn't, it wouldn't be able to tell you your balance without scanning the whole blockchain every startup or every new transaction.

A wallet file of 2MB is miniscule in comparison to the blockchian. Eventually the size does affect performance, but only when magnitudes in size larger. As a pool, the only thing coming in will be 50 BTCs and the only thing going out will be payments to miners; these two should be separate anyway. The payment wallet can have it's balance sent to a new empty wallet if it begins taking too much processing overhead.

[steve15]

Or just change your wallet. There a numerous better wallet's out there!