The Slow Queries. When you debug an instance you can either enable SQL debugging to look for slow queries or you can look for slow queries by checking the Slow Queries sys_query_pattern table by navigating to System Diagnostics Stats Slow Queries. To find the slow queries well need to log them either from Solr or from the application that queries it.
However it may also be a good idea to check the queries that are being run against that database. It lists data with the slowest performing first. For more on application response times and user satisfaction check out the Apdex metric.
This table stores all the slow queries in the instance.
Detecting Slow Queries. Start monitoring the slow query logfile. Whenever something is slow you can respond instantly to any individual query which exceeds the desired threshold. Slow Query Log Overview.