ishmael.wikimedia.org was a visual tool to show MySQL statistics and analyze MySQL query logs. It has been superseded by Tendril and decommissioned in October 2015.
MySQL's slow query log is a file local to the DB that requires shell access to the db server - http://dev.mysql.com/doc/refman/5.0/en/slow-query-log.html describes it. Asher set up ishmael, a web tool to analyze slow queries, circa 2011.
In 2013, Asher wrote:
- if you're interested in production query performance histograms, I recommend looking at those generated from random samples of all queries in addition to just those that make the slow query logs.
- Links to both of those views for every db are provided on http://noc.wikimedia.org/dbtree/ .