- SQL server performance analysis. It is used to display the database buffer hit ratio. It is recommended that it should not be less than 94% i.e. for every hundred reads only 6 should goes to the database.
- Database hit ratio comes down below 94% then consider the following.
1. Frequent updates on the database
2. DB Buffer size is not sufficient to hold the content fetched from the database.
It is calculated by using formulae
[ Logical reads - Physical Reads]/ Logical Reads * 100
Logical Reads is the sum of [Physical reads and Buffer Reads] (Buffer Gets/ Reads)
Physical Reads: The reads from the database.
If the buffer hit ratio comes down it effects on the DB response time.
Ensure that DB Buffers are configured as per the available memory. Some times complete memory will be dedicated to DB Buffers.