Is transaction order consistent within a finalized block retrieved from the RPC API?

Question

https://docs.solana.com/developing/clients/jsonrpc-api#getblock

Will the order of transactions in the block, be consistent if requested again on a different node or at a different time?

I understand that some transactions can be processed concurrently. This makes me question whether the ordering within the returned block is arbitrary or deterministic or locked.

Answer 1

If transaction have data dependencies, they will be stored sequentially in the block inside a special section called an entry that requires ordering.

If there are no data dependencies (e.g. some tx writing to some account and the next tx reading from it), then things can explicitly be randomized, and execution order is not guaranteed.

See also this question.