Skip to content

Commit

Permalink
Update transaction-isolation-levels.md
Browse files Browse the repository at this point in the history
  • Loading branch information
TomShawn authored Sep 8, 2021
1 parent 6fc863f commit a20688e
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion transaction-isolation-levels.md
Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@ The Repeatable Read isolation level in TiDB differs from ANSI Repeatable Read is

### Difference between TiDB and MySQL Repeatable Read

The Repeatable Read isolation level in TiDB differs from that in MySQL. The MySQL Repeatable Read isolation level does not check whether the current version is visible when updating, which means it can continue to update even if the row has been updated after the transaction starts. In contrast, if the row has been updated after the transaction starts, the TiDB optimistic transaction is rolled back and retried. Transaction Retries in TiDB's optimistic concurrency control might fail, leading to a final failure of the transaction, while in TiDB's pessimistic concurrency control and MySQL, the updating transaction can be successful.
The Repeatable Read isolation level in TiDB differs from that in MySQL. The MySQL Repeatable Read isolation level does not check whether the current version is visible when updating, which means it can continue to update even if the row has been updated after the transaction starts. In contrast, if the row has been updated after the transaction starts, the TiDB optimistic transaction is rolled back and retried. Transaction retries in TiDB's optimistic concurrency control might fail, leading to a final failure of the transaction, while in TiDB's pessimistic concurrency control and MySQL, the updating transaction can be successful.

## Read Committed isolation level

Expand Down

0 comments on commit a20688e

Please sign in to comment.