8.0 went GA in April and the correlated subquery can retire. The plans before and after, the recursive CTE that replaces a loop, and the upgrade nobody expects.
Earlier versions accepted DESC in an index definition and ignored it, which is worse than rejecting it because the query looked optimised and was doing a filesort. It…
The character set named utf8 in MySQL has always been a three-byte subset that cannot store an emoji or several CJK characters, and 8.0 makes the four-byte one…
8.0 defaults to utf8mb4_0900_ai_ci, which sorts and compares differently from the utf8mb4_general_ci a 5.7 database is almost certainly using — and a join between two columns with different…