Question about wallet.dat and bitcoin core

[73blazer]

Under bitcoin core (currently 0.20.1) full node full chain I'm just curious why wallet.dat file keeps changing a few times day even though I've made no transactions nor generated any new addy's or done anything??? I understand and expect stuff in blocks dir and chainstate dir to change but why is wallet.dat file changing?

[ranochigo]

As your Bitcoin Core synchronizes, it indexes transactions that are relevant to the addresses within the wallet.dat. It periodically (or when starting up or shutting down the client) writes to your wallet.dat file the best tip which is the latest block so that it is able to keep track of the point whereby the transactions related to your wallet.dat weren't parsed.

The wallet.dat isn't readable as it's in berkeleydb but you can dumpwallet and see that it does actually indicate the hash of the block where your client has synchronized to.

[73blazer]

Ahh, ok. Makes sense. I used to only back it up manually after I've made some transaction (I only do a few transaction/year), but recently I put in an offsite backup job and it's backing up stuff that has changed every hour now and I see in the log getting backed up several times/day, was just wondering why.