Dirty read
| Chronologically | Transfer | Withdrawals |
|---|---|---|
| 1 | Open affairs | |
| 2 | Open affairs | |
| 3 | Balance inquiries 10000 | |
| 4 | Withdrawals of 1,000 yuan, 9000 yuan balance | |
| 5 | Query limit 9000 yuan | |
| 6 | An unknown error has occurred, things happen rolled back 10,000 yuan | |
| 7 | 2000 came into updating the new balance of 11,000 | |
| 8 | Submit things | |
| Normal logic 12,000 yuan |
Non-repeatable read
| Time slice | A transaction | Transaction B |
|---|---|---|
| 1 | Open affairs | |
| 2 | The first query, the balance of 10,000 yuan | |
| 3 | Open affairs | |
| 4 | operating | |
| 5 | Changed the balance of 20,000 yuan | |
| 6 | Commit the transaction | |
| 7 | Queries balance of 20,000 yuan | |
| The results of previous inquiries and a post should be consistent |
Magic Reading
statistics
| Time slice | A transaction | Transaction B |
|---|---|---|
| 1 | Open affairs | |
| 2 | First count, the data amount 100 | |
| 3 | Open affairs | |
| 4 | other things | |
| 5 | Insert 100 data | |
| 6 | submit | |
| 7 | The second is 200 | |
| Magic Reading |
pip install pymysql -i https:/pypi.douban.com/simple
