V$REQDIST lists statistics for the histogram of shared server dispatcher request times, divided into 12 buckets, or ranges of time. The time ranges grow exponentially as a function of the bucket number.
Bucket number: 0 - 11; the maximum time for each bucket is (4 * 2^N)/100 seconds
Count of requests whose total time to complete (excluding wait time) falls in this range
The ID of the container to which the data pertains. Possible values include:
0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data