Observing Delay in clearing the item count upon delete operation

Hi ,

When I insert large number of items into couchbase and then delete all those items in a loop, I am still seeing the item count in the “Data Buckets” tab of GUI( Op/sec is 0). It takes about 30 -60 seconds for item count to become 0 even though all delete operations are notified as success in the couchbase client.Is this delay normal.

Does this mean the items are still present in the couchbase during that 30-60 second period ? Will it be available if we do a fetch operation?
Or Is it marked for delete and not accessible?.

Please let me know about this behavior