The Exalead CloudView index is generational. When indexing documents, they are divided into batches known as
jobs.
Each time a job is indexed, it creates a new generation of the index. Exalead CloudView stores this new generation of the index in a data structure called a slot. Each new slot
is appended to the original index. Once the latest generation is committed to the index, the
index replicas are updated.
At search time, Exalead CloudView searches in all these slots of all the index replicas, and merges the results to return
the final result set. From time to time, slots are compacted to create an index with fewer
slots, for more efficient searching.