Query shows SQL in the SGA where there are a large number of similar statements

The following query shows SQL in the SGA where there are a large number of similar statements:

SELECT substr(sql_text,1,40) "SQL",count(*),sum(executions) "TotalExecs"
FROM v$sqlarea
WHERE executions < 5
GROUP BY substr(sql_text,1,40)
HAVING count(*) > 30
ORDER BY 2;

Note: If there is latch contention for the library cache latches the above statement may cause yet further contention problems.