UTXO与帐户模型

首先,utxos和帐户没有什么不同.您可以将(account, counter)对视为几乎等同于utxo.

主要原因与并发访问智能合约有关.在大多数情况下,同一智能合约的两笔交易将通勤(或几乎通勤),因此,发件人无需知道哪些其他交易正在影响同一区块中的该特定合同.

例如,想象一下一个出售机票的合同.在飞机满员之前,该合同的交易将继续进行.我买机票和买机票可以同时发生.

如果我们尝试将UTXO模型扩展到智能合约,那么当我购买机票时,该合约在某种意义上将被销毁,并且将使用不同的处理方式重新创建销售少一张机票的类似合约.我们将无法同时访问同一区块中的合同.

如果需要这种行为,则可以通过基于帐户的智能合约系统来模拟.例如,合同可能要求与其进行的每个交易都必须传递其当前存储的哈希值.但是,事实并非如此.

因此,基于帐户的系统更具表现力.

First off, utxos and accounts aren't that different. You can look at the pair (account, counter) as almost equivalent to a utxo.

The main reason has to do with concurrent access to smart contracts. In most cases, two transactions to the same smart-contract will commute (or almost commute) and therefore the senders do not need to know what other transactions are affecting this particular contract in the same block.

For instance, imagine a contract selling plane tickets. Until the plane is full, transactions to that contract will commute. My buying a plane ticket and your buying a plane ticket can happen at the same time.

If we try and extend the UTXO model to smart-contracts, as soon as I buy my plane ticket, the contract would in a sense be destroyed, and a similar contract selling one fewer ticket would be recreated with a different handle. We would not both be able to access that contract in the same block.

If this behavior is desired, it can be emulated by an account based smart-contract system. For instance, a contract could require that every transaction to it must pass a hash of its current storage. However, the reverse is not true.

Therefore, the account based system is more expressive.