hello, I want to know about the leftmost index prefixes using nounique index/
About the composite index using primary key, in the reference 7.4.5, I can understand the following: -------------------------------------------------------------------------------------------------- MySQL can see that if a column is a leftmost prefix of the primary key, I can use it as though it were a separate index. I don't need to define a second index on the column alone. On the other hand, if a column is not a leftmost, I need to define a second index . -------------------------------------------------------------------------------------------------- Is the above content legal about the leftmost index prefixes using nounique index?
