Question about Read Set

STBoo

Below diagram taken from charter 7. The Lifecycle of A Transaction -> Ordering Service in Hyperledger Fabric

Below diagram taken from https://hyperledger-fabric.readthedocs.io/en/release-2.2/readwrite.html

The statement from the course and document is different, is the read set contains only key and version number but no value or contains the key/value pairs like the write set?

Bobbijn

STBoo, Hello, I can see your confusion. The function of the Transaction simulation is to collect/check the read sets and write sets for duplication that might cause inconsistencies in the ledger. During this simulation a check is performed to assure there aren't any read and write sets from/to the same key/value pair in the same block. The read set contains the unique keys and the committed version numbers, because it a read function, no values are associated with it . The write set contains a list of unique keys as well and the new value from the transactions. It is looking to eliminate any inconsistencies with the transactions ordering. Please refer to the The Life cycle of a transaction slideshow in chapter 7 for further clarification.

Hope this helps. Keep Learning, Bobbi.

STBoo

@Bobbijn, thanks for your reply. the slideshow in chapter 7 does not reveal more info for the read-write set than the screen i captured. IMHO, your explanation provide more detail info for the read-write set. Please consider to include this info to the course material.