Identifying free list contention

To identify the percentage of requests that resulted in a wait for a free block run the following query:

select round( (sum(decode(w.class,'free list',count,0))
    / (sum(decode(name,'db block gets', value, 0))
    + sum(decode(name,'consistent gets', value, 0)))) * 100,2)
    from v$waitstat w, v$sysstat;

This should be less than 1%. To reduce contention for a table’s free list the table must be recreated with a larger value in the FREELISTS storage parameter.

This page represents one page of many pages of notes I made whilst working with Oracle 7 through to 10i. I now no longer work with Oracle databases, but hope that these notes will continue to be of benefit to others.