Last updated
Last updated
MVCC eliminates locking so that read operations doesn't need to be block by write operations.
For example, a thread executing UPDATE statement should not block SELECT statement by another thread.
Every read and write operation are serialized.
Within MySQL, it uses next-key lock to implement MVCC, so it does not have the problem for phantom read.
Only exist in Read committed and Repeatable read mode.
When a transaction (originally started but uncommitted when the target transaction starts, namely if transaction_id < curr_transaction_id) is committed, a new readview will be generated.
Once the readview is generated, it won't be updated.
index and schema design
分析磁盘I/O时间
Problems of mySQL:
Isolation level:
