I'm also surprised chainstate folder has size 7.8GB. So i decide to run
gettxoutsetinfo and got following statistic which state there are currently 116.8 million UTXO.
{
"height": 2810692,
"bestblock": "000000000000009910d22b6f04ef25d718350863560ea24a85da54e666127e4f",
"txouts": 116842453,
"bogosize": 9425932147,
"hash_serialized_3": "ba355559e0d1c5de59ec7e512a7ef374e0df01be653d60424db397cd84dae801",
"total_amount": 20997039.32915585,
"transactions": 64934575,
"disk_size": 8364679205
}
I think that is larger than even the bitcoin mainnet's chainstate, right? It was at 6GB or so the last time I checked its size.
But the fact that there is a ballooning UTXO set on testnet does not surprise me at all, as people rarely spend their coins after they are finish testing something. At best, they just return it to the faucet they got it from.