Why MySQL Doesn’t Always Use an Index
Share

You add an index, run EXPLAIN, and see key: NULL. That can mean MySQL estimated that another access method would cost less, or that the…

 

 You add an index, run EXPLAIN, and see key: NULL. That can mean MySQL estimated that another access method would cost less, or that the…Continue reading on Medium » Read More MySQL on Medium 

#sql

By ali

Leave a Reply