Homework on Mempool - Questions

Blockchain and Bitcoin 101
#2169

  1. The mempool is a database of unconfirmed UTXOs that are yet to be mined by a miner.

  2. The mempool becomes larger in size which eventually leads to a miner reaching full-capacity in bytes. Therefore, not being able to record anymore newly unconfirmed transactions.

If we mean the rate (fee) of the new transaction?

If a UTXO was spent with very low fee then it is possible that miners may never mine it or take longer than usual to do so. This is especially the case during periods where demands for space on the mempool are high, inflating the value per byte. Miners by default are incentivised to mining transactions that provide high rewards.

  1. The more bytes taken up by the transactions, the higher the fees become to mine them. Miners would have to prioritise confirming multiple unspent transactions which were output from any same wallet as part of clearing the mempool space across the blockchain.

This means any wallet outputting only a single UTXO which contains a significant value in satoshis would have to take less precedence because they may take less space (bytes) in the mempool compared to the wallets that initiated multiple UTXO transactions at the time.

Even if the the individual who sent the single UTXO had set a very high fee for it to be mined onto the next block.

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#2170

  1. A place for unconfirmed transactions while they wait for a miner.

  2. Longer transactions times.

  3. Higher fees to incentivize miners to work more.

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#2171
  1. What is the mempool? A mempool is the internal memory of a node that stores all unconfirmed transactions that has been verified (makes sense).
  2. What happens if the miners can’t keep up with the rate of the new transaction? The mempool will increase in transactions and the fees will also increase.
  3. How does a growing mempool effect transaction fees? The fees will increase on some transactions so they get added fast to a miners block.
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#2172

  1. What is the mempool?
    The mempool is the space where can stay the transaction in waiting for a miner to confirm it.

  2. What happens if the miners can’t keep up with the rate of the new transaction?
    The mempool will grow, then the average fee is going to be higher.

  3. How does a growing mempool effect transaction fees?
    When the mempool is growing, the miners will give priority to transactions with the highest fee, that means transactions with lower fee have to wait longer.

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#2173

I’m not entirely sure what you mean by that. Miners mostly only care about the sat/byte ratio and will prioritize transactions that have a high ratio. If a tx uses one UTXO and has a small fee, miners will pick it up first. :slight_smile:

#2174
  1. Mempool is a pool of all unconfirmed transactions waiting to be picked up by miners
  2. The fees go up, and takes more time to confirm, connection on the blockchain
    3.fees go up
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#2175
  1. What is the mempool?
  • This is where unconfirmed tx are held until they are selected by the miner to become part of the next block.
  1. What happens if the miners can’t keep up with the rate of the new transaction?
  • The pool will grow and transaction processing time will likely slow as a result
  1. How does a growing mempool effect transaction fees?
  • Fees will go up demand outpaces supply and while higher fees are processed first
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#2176
  1. transactions waiting to be included in a mined block exist in the mempool
  2. the mempool size increases and transactions with higher fees will jump the line
  3. If you want your xaction to be mined, it will need to have a higher xaction fee.
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#2177
  1. Mempool is a database which stores unconfirmed transactions.
    2.The unconfirmed transactions in mempool increases.
  2. When there is more unconfirmed transaction in mempool, the miners processes the transaction with higher fees first. This leads to increase in transaction fees in order to be added in the blockchain fast.
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#2178
  1. Data structure of unspent TX’s.
  2. The mempool size increases.
  3. Those with higher fees will have an advantage.
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#2179
  1. What is the mempool?
    List of unconfirmed transactions. Miner pick TX from mempool. Miner prioritize TX with higher fee.
  2. What happens if the miners can’t keep up with the rate of the new transaction?
    Time to execute transaction will increase.
  3. How does a growing mempool effect transaction fees?
    TX fee to execute your transaction will be higher. Because miners picks TX with highest fee.
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#2180

  1. A mempool shows how many transactions are unconfirmed and what kind of fees they have. It is the place that all nodes have where the unconfirmed transactions go before they are picked up by a miner.

  2. If the miners can’t keep up with the rate of the new transaction then the mempool will increase in size and raise fees due to the increase in miner demand.

  3. A growing mempool will increase the average transaction fee due to the demand for miners outpacing the supply.

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#2181

@Alko89 I thought miners were only incentivized picking up transactions that offered high fees mainly since it gives them higher reward but I thought miners would have to prioritise transactions which were output from several UTXOs over the former I mentioned due to those taking more block space even if the value per byte was lower than the transaction fee? :confused:

I had to listen to Mempool lesson @7:40 - 9:46 part several times to understand what Ivan was saying since he said how multiple UTXOs being spent to form a whole transaction would take more space in bytes to represent in binary than one where you had a single UTXO with a large value and even if it is giving more reward for the space it is taking.

Not sure if I got the right idea :confused:

#2182

1- the place where the transactions that were not confirmed are temporarily located
2- the mem pool makes a copy of the record
3-increases the value of transaction fees

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#2183

If the value per byte is lower they will of course not accept a larger transaction.
For example if a block would only be able to accept 10 UTXOs in a block and there are 12 transactions in the mempool, two of them have 5 UTXOs as an input and the rest have 1 UTXO.
If for example these two 5 UTXO txs would pay a fee of 10 sat each, that would mean they are willing to pay a fee 2 sat per UTXO.
The 1 UTXO transactions only pay 1 sat per UTXO.
In this case a miner will prefer the two larger transactions because he would get in total of 20 sat of fees while he would only get 10 sat if he would accept the smaller cheaper txs. :slight_smile:

#2184
  1. A data structure of unconfirmed transactions that each node has.
  2. The mempool grows bigger. Miners will, in that case, pick the transaction with the highest fee first (financial incentive).
  3. You will have to pay a higher fee in order for the transaction to go through.
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#2185

@Alko89 I see, that makes a lot of sense now :slight_smile: thanks for taking the time to explaining to me this! :+1:

#2186
  1. The mempool is a data structure in which all unconfirmed transactions wait to be added to a block by a miner.

2 . There mempool will grow in size, as well as there average fee will grow.

  1. When the mempool grows the average transactions fees will also rise because people are pricing their fees competitively to get into a block in a timely fashion.
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#2187

  1. When a wallet broadcasts a transaction, it is not immediately added to the ledger but rather it is broadcasted in the mempool to all Miners/nodes so that they can add it to a new block in the ledger.

  2. If Miners are unable to keep up with the rate of new transactions the Mempool grows and wait times for confirmation increases. This is called congestion in blockchain terms.

  3. The the transactions with higher fees are more likely to be added first from the Mempool to a new block. This will increase the overall average fees since users will try to outbid each other to get accepted first.

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#2188

  1. A mempool is a data structure of unconfirmed transactions or UTXO’s that each node has

  2. The mempool grows larger and transactions take longer to process

  3. Larger mempool means larger transaction fees. Miners have more incentive to complete transactions as people offer more fees to move their transactions quicker

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