3 ms·

Thanks for reply. So in my understanding: - The transactions that only touch one shard is simple - The transactions that read multiple shards but only write

by qouteall 10mo ago

Thanks for reply. So in my understanding: - The transactions that only touch one shard is simple - The transactions that read multiple shards but only write shard can use simple optimistic concurrency control - The transactions that writes (and reads) multiple shards stay complex. Can be avoided by designing a smart sharding key. (hard to do if business requirement is complex)

n2d4 10mo ago
That's right! If you anticipate you will encounter the third type a lot, and you don't anticipate that you will need to shard either way, what I'm talking about here makes no sense for you.
qouteall 10mo ago
The optimistic concurrency control that reads multiple shards cannot use simple CAS. It probably needs to do something like two-phase committing