MySQL Forums
Forum List  »  InnoDB

MVCC - The atomicity problem of consistent reads
Posted by: Y M
Date: September 02, 2021 11:09AM

Reading and writing to the same tuple at the same time may cause read logic exceptions because of the non-atomic action of writing to the override of the tuple.

For MVCC in MySql,
Conceptually, because of ReadView, access to the tuple being written can be avoided by visibility rules, and then the race between reads and writes occurring in the same region can be avoided
But in terms of implementation details, I still have a question:
Overwriting a field of a tuple will replace the data in the heap. If a read operation comes in, the same area will be read and written, which may result in read and write conflicts (byte copying is not atomic).
How can I avoid this read-write conflict? Is it a lock?

Options: ReplyQuote

Written By
MVCC - The atomicity problem of consistent reads
September 02, 2021 11:09AM

Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.