Slide 6
Slide 6 text
THE POWER OF INDEX
➤ Lack of good indexes can cause expensive queries
➤ Expensive queries are very good at making other healthy/simple
queries running slow (e.g. high resource usage, locks, etc.)
➤ Always think about adding/revisiting indexes when you create
new tables, introducing and/or modifying new columns, queries
➤ Watch out unused indexes, but also keep it in your mind that
these indexes may be used in followers
➤ the cost of maintaining the index v.s. the benefits the index
provides for queries
➤ I/O is expensive (make sure cache hit rate is high!), good indexes
will help reducing disk I/O and keep good cache