title: are index page reads tracked in mysql 5.5 performance_schema tables?
body: <p>My question is about mysql's internal tracking of index usage.<br>
  I wish to know if particular indexes are being used. In other DBMSs there are infrastructure tables that track page_reads and page_hits for objects like tables and indexes.  I see in the file_summary_by_instance table that table file names are tracked along with the count of reads and the total bytes read.  Do we have anything like that that tracks indexes?</p>