1  –  root-file-spec

    The file specification for the database root file to be analyzed.
    The default file extension is .rdb.

2  –  index-name

    index-name[,...]

    The name of the index for which you want information. The default
    is all enabled indexes. If you want information about a disabled
    index, you must specify it by name. This parameter is optional.
    An indirect file reference can be used.