We all know that the purpose of creating an index is to quickly and selectively read a subset of the entire collection that meets the criteria. A table in MySQL can support multiple indexes. However, when you write your SQL statement, you do not actively specify which index to use. Have you ever encountered an SQL statement that creates an index but does not use the index, or an otherwise fast statement that is slow because MySQL chose the wrong index? Full optimization and utilization of indexes can greatly improve data query efficiency, but in practical applications MySQL may not always choose appropriate and efficient indexes
We all know that the purpose of creating an index is to quickly and selectively read a subset of the entire collection that meets the criteria. A table in MySQL can support multiple indexes. However, when you write your SQL statement, you do not actively specify which index to use. Have you ever encountered an SQL statement that creates an index but does not use the index, or an otherwise fast statement that is slow because MySQL chose the wrong index? Full optimization and utilization of indexes can greatly improve data query efficiency, but in practical applications MySQL may not always choose appropriate and efficient indexesCopy the code- 12121212
We all know that the purpose of creating an index is to quickly and selectively read a subset of the entire collection that meets the criteria. A table in MySQL can support multiple indexes. However, when you write your SQL statement, you do not actively specify which index to use. Have you ever encountered an SQL statement that creates an index but does not use the index, or an otherwise fast statement that is slow because MySQL chose the wrong index