Other day I was thinking, where goes/stay the unconfirmed transactions? It stay on the blockchain too?
Well, maybe we can stop sending btc for 24 hours, one day per year to unstuck this transactions...
And what happens if we got a flood of 1 satoshi transactions without fee?
Unconfirmed transaction are not stored in the Bitcoin blockchain.
They are temporary held in the memory pool of all Bitcoin nodes in the network.
When a miner "finds" a block and "adds" transactions into that block, they are
removed from the memory pools and written into the blockchain.
After a few days, if a tx does not enter a block, those pending txs will be automatically
dropped from the memory pool and "returned" to the original address. Then the tx will
need to be performed again with an appropriate fee.
All txs that have no fee or a very low fee, are usually ignored by a majority of nodes
in the network. During "spam attacks" most nodes are set to ignore those "attack txs".