Mempool

What Is A Mempool?

A mempool is a temporary database that stores all unconfirmed transactions in a blockchain. Mempool is formed from two words: memory and pool. A mempool, to put it another way, is a collection of the overall legitimate transactions that are made but have yet to be validated by a blockchain network. A mempool can also be referred to as the waiting room that has not been added to the block.

Deeper Definition

A transaction spreads out from a node and propagates until it is included in a block. While all of this is going on, these transactions remain in the “waiting room.” A set of checks is performed on the transaction while it is in the mempool, and signatures, outputs, and inputs are verified. Once the transaction’s details have been validated, the transaction departs the mempool and is added to a block. The transaction is refused if it is not verified.

The mempool size of a blockchain could provide some information concerning the network. For example, a large mempool size indicates higher network traffic on a blockchain. This also shows an average transaction confirmation time and, of course, a higher priority fee. Confirmation time is the time taken for a transaction to be confirmed.

Putting in mind the tremendous amount of crypto-transactions made on a network, one might begin to wonder how the mempool stays “sane.” Mempools remain “sane” by prioritizing transactions by setting a transaction fee threshold. This is the minimum transaction fee that will allow a transaction to enter into a mempool. The mempool keeps taking in transaction data once the number of transactions reaches the peak of its capability, creating a transaction fee threshold. All transactions below that fee are kicked out of the mempool, and all incoming transactions below are denied access into the pool.

However, many blockchain users pay a higher fee called the “priority fee.” This is basically “bribing” the mempool to allow a transaction to be processed and give the transaction priority over other transactions.

Mempool Example

A lot of pending transactions are stored in the mempool in cryptocurrency Ethereum as they await approval. A transaction that is yet to be affected is stored there and then, as soon as it can be sorted, the mempool is accessed for that purpose.