Buffer Cache Hit Ratio Very Low.
Applies to: Microsoft SQL Server 2000
 
Problem Description.
We were seeing low readings for the buffer cache hit ratio two days in a row on 
a SQL Server 2000 instance. The ratio was 3.15% in average the first day.  
On the second day the ratio was 33.28% in average.
Cause.
We discovered that on the first day was installed the agent of a backup 
application software, reducing the available memory on the server. The server 
had only 3.24 MB of available memory (RAM) in average that day.  The second 
day, 37.80 MB was the average.
The cause of the low readings was insufficient RAM.
Solution.
After freeing some RAM or adding more memory to your server you will see the 
readings back to normal.