https://blog.csdn.net/helloxiaozhe/article/details/77427266
The use replace brought
1, Replace into operation in the unique key duplication, it is the first attempt to write, a collision is detected then delete the original record, and then write a new record. This operation is only a binary log update operation will result in the same table auto_increment value from the main inconsistency, the master-slave switching, business writing failure easily induced;
2, according to Description 1, there are two primary operating DB write operation Replace into the worst case, the operation burden;
3, the concurrency, Replace into problems due to the different order of acquisition session lock, the higher the probability of generating a deadlock;
ABC election