MySQL index maintenance and optimization--find duplicate and redundant indexes

Method One: Find duplicate and redundant indexes through MySQL's INFORMATION_SCHEMA database

SELECTA.table_schema as 'Database', A.table_name as 'Table name', A.index_name as 'Index 1', B.index_name as 'Index 2', A.column_name as 'repeating column names' fromInformation_schema.StatisticsaJOIN StatisticsB onA.table_schema=B.table_schema andA.table_name=B.table_name andA.seq_in_index=B.seq_in_index andA.column_name=B.column_nameWHEREA.seq_in_index= 1     andA.index_name!=B.index_name

Method Two: Through tools

Use the PT-Duplicate-key-checker tool to check for duplicate and redundant index usage pt-Duplicate  -key----pxxx

Finding duplicate and redundant indexes

Reference to MU-class network: http://www.imooc.com/video/3998

MySQL index maintenance and optimization--find duplicate and redundant indexes