A compressed file in an index bucket that contains event data, as well as journal information that the indexer can use to reconstitute the index's index files. The rawdata file and the index files together constitute the files in a bucket.
In an indexer cluster, a searchable copy of a bucket contains both the rawdata file and a set of index files. A non-searchable copy contains only the rawdata file.
For more information
In Managing Indexers and Clusters of Indexers: