Advanced MySQL 8

Getting rid of unused and duplicate indexes

We all know now that indexes can mean the difference between a high-performance database and a slow query. Over time, indexes will need occasional maintenance to see whether you have indexes that are no longer useful or are duplicates.

MySQL 5.7.7, introduced a new schema called SYS. MySQL uses a set of objects found in this new schema to assist DBAs and developers in reading collected data from the performance schema. The objects that you'll find in the SYS schema can be used for typical cases of optimization and diagnostics. The objects in this scheme include the following:

• VIEWS that summarize schema performance data in a more convenient and easier form
• Stored procedures and stored functions ...