Q: About some transactions no miners pick up

[tsubasa1380]

[ About some transactions no miners pick up ]

If some transactions no miners pick up from their memory pools because of low fee compared to transaction size,
what will happen to these transactions in the future?

It is said that most miners drop transactions over 72 hours old from their memory pools.
(e.g. https://support.21.co/bitcoin/transactions-and-fees/how-to-look-up-whether-your-transaction-spent-an-unconfirmed-output)

Is there any possibility that bitcoins used for these transactions will be lost?

[DannyHamilton]

[ About some transactions no miners pick up ]

If some transactions no miners pick up from their memory pools because of low fee compared to transaction size,
what will happen to these transactions in the future?

They will be forgotten about unless someone re-broadcasts them.

It is said that most miners drop transactions over 72 hours old from their memory pools.

There is no requirement for a miner to keep the transaction in their mempool for any amount of time.  72 hours does appear to be a popular common setting.

Is there any possibility that bitcoins used for these transactions will be lost?

If someone loses their private keys, then they will be unable to spend their bitcoins.  The bitcoins effectively don't move until the transaction is confirmed. Therefore, they are still accessible to the sender until the transaction confirms.  Once the transaction is confirmed, the bitcoins are only accessible to the receiver.  There is no intermediate place for the bitcoins.  They are either available to the sender or to the receiver as long as they have their private keys.

[tsubasa1380]

Thank you for your prompt reply.

If someone loses their private keys, then they will be unable to spend their bitcoins.  The bitcoins effectively don't move until the transaction is confirmed. Therefore, they are still accessible to the sender until the transaction confirms.  Once the transaction is confirmed, the bitcoins are only accessible to the receiver.  There is no intermediate place for the bitcoins.  They are either available to the sender or to the receiver as long as they have their private keys.

In this case I have one more question.

If the sender make the second transaction of which inputs are the first transaction txid to accomplish the first transaction and re-send the second transaction with higher fee compare to normal transaction size, then will some miners include the second transaction into blockchain?

If so,the receiver will be able to get bitcoins.

Is this right?

[Potato Chips]

Thank you for your prompt reply.

If someone loses their private keys, then they will be unable to spend their bitcoins.  The bitcoins effectively don't move until the transaction is confirmed. Therefore, they are still accessible to the sender until the transaction confirms.  Once the transaction is confirmed, the bitcoins are only accessible to the receiver.  There is no intermediate place for the bitcoins.  They are either available to the sender or to the receiver as long as they have their private keys.

In this case I have one more question.

If the sender make the second transaction of which inputs are the first transaction txid to accomplish the first transaction and re-send the second transaction with higher fee compare to normal transaction size, then will some miners include the second transaction into blockchain?

If so,the receiver will be able to get bitcoins.

Is this right?

In other words you'll be creating two transactions that spends the same bitcoins but the other one will have a higher fee? 

The literal double spending has never happened in bitcoin because if there are transactions which tagged as "double spent" the first one to receive confirmations becomes the official and the rest will be invalid. In most cases if the first transaction's miner fee is too low the one which has the sufficient or higher fee gets confirmed first so the first one will be invalid.

[AGD]

Thank you for your prompt reply.

If someone loses their private keys, then they will be unable to spend their bitcoins.  The bitcoins effectively don't move until the transaction is confirmed. Therefore, they are still accessible to the sender until the transaction confirms.  Once the transaction is confirmed, the bitcoins are only accessible to the receiver.  There is no intermediate place for the bitcoins.  They are either available to the sender or to the receiver as long as they have their private keys.

In this case I have one more question.

If the sender make the second transaction of which inputs are the first transaction txid to accomplish the first transaction and re-send the second transaction with higher fee compare to normal transaction size, then will some miners include the second transaction into blockchain?

If so,the receiver will be able to get bitcoins.

Is this right?

Yes, that's right as long as the first transaction hasn't been confirmed.