Blockchain technology offers a revolutionary solution for the security and tracking of digital asset transfers. However, the need to manage large-scale transaction volumes challenges traditional blockchain structures. This is where new approaches such as parallel and optimistic execution come into play.
Blockchain networks collect a series of transactions within a block and execute these transactions sequentially. However, this method can extend transaction times and limit the scalability of the network. Parallel execution allows transactions to be executed simultaneously, thereby increasing transaction speed and expanding the network’s capacity.
For example, transfer transactions between different accounts within a block can be executed in parallel. This shortens transaction time and provides a faster network. However, the dependencies of the transactions must be considered and appropriately managed.
Optimistic execution allows the next transaction to be initiated without waiting for the completion of the current transaction. This reduces transaction times while increasing network efficiency. However, it carries the risk of incorrect execution.
Specifically, if there is a dependency between two transactions on the same account and these transactions are executed in parallel, the results may be inconsistent. Therefore, an optimistic execution strategy should include a mechanism that carefully monitors transaction results and re-executes them if necessary.
The development of blockchain technology is supported by innovative approaches such as parallel and optimistic execution. These approaches increase transaction speed while maintaining security and enhancing the network’s scalability.
To simplify parallelized optimistic execution, consider the analogy of traffic lights in a city. At an intersection, traffic lights exist. Each light turns green in sequence, allowing cars to pass. This is akin to blocks being proposed by a single proposer in a Proof-of-Stake consensus. Each traffic light represents a block’s proposer, waiting for approval.
Optimistic execution can be likened to the functionality of traffic lights. Normally, before allowing a vehicle to pass, we wait for the approval of other lights. However, sometimes traffic is light, and instead of waiting for approval from other lights, we "guess" and turn the next light green to keep traffic flowing. This means executing transactions before the blocks are confirmed.
Usually, the "optimistic" behavior of traffic lights succeeds and speeds up the flow of traffic because most blocks are confirmed on the first round, allowing us to execute transactions without waiting for other lights' approval. However, sometimes traffic lights can make incorrect predictions, causing traffic jams.
Parallel execution can be likened to vehicles coming from different directions passing simultaneously. For example, if vehicles are coming from different directions at an intersection and there is no risk of collision, the traffic lights can allow these vehicles to pass at the same time. Similarly, transactions in a blockchain can be executed simultaneously when they do not interact with each other, increasing transaction speed.
However, sometimes there is a risk of collision between vehicles, and in such cases, there is a dependency between the lights. For instance, if vehicles moving in the same direction carry the risk of collision, the traffic lights regulate the passage of these vehicles sequentially. Similarly, dependent transactions in a blockchain are also executed sequentially.
Parallelized optimistic execution is a promising approach to enhance the scalability and efficiency of blockchain networks. By enabling simultaneous transaction execution and reducing waiting times through optimistic strategies, these methods can significantly improve the performance of blockchain systems. However, careful management of transaction dependencies and mechanisms for monitoring and correcting execution errors are essential to maintain the integrity and reliability of the network.