1  –  node_removals_field

    This field gives the total number of index entries within the
    root, leaf, and duplicate nodes that have been removed. This
    removal can be triggered by erasing rows, deleting tables, or
    deleting indexes. The calculation of node removals minus the sum
    of the root, leaf, and duplicate node removals yields the number
    of entries removed from mid-level nodes. A node is not deleted
    until all its entries are removed.

2  –  _root_removals_field

    This field gives the number of index entries removed from a root
    node due to deletion of entries within lower-level nodes. If an
    index consists of only one node, removals from this node are not
    included in this field, but are included in the "leaf removals"
    field.

3  –  _leaf_removals_field

    This field gives the number of unique index keys removed from the
    leaf nodes during an SQL DELETE operation.

4  –  _dup__removals_field

    This field gives the number of duplicate index keys removed from
    duplicate nodes due to the deletion of duplicate records. This
    should be a one-to-one correspondence to the number of erased
    duplicate records within the database.

5  –  node_deletions_field

    This field gives the total number of index nodes deleted due
    to an SQL DROP INDEX statement or when the nodes become empty
    (except for the root node, which remains even when it is empty).
    When an index is deleted, this number should be equal to the
    total number of index nodes within the index. This field minus
    the sum of leaf and duplicate node deletions yields the number of
    mid-level node deletions.

6  –  _leaf_deletions_field

    This field gives the number of leaf (bottom level) nodes deleted
    from the database's indexes. A leaf node is deleted only when it
    becomes empty.

7  –  _dup__deletions_field

    This field gives the number of duplicate node deletions within
    the indexes.

8  –  index_destructions_field

    This field gives the number of indexes deleted with an SQL
    DROP INDEX statement. This count will be 1 if the index is not
    partitioned. If an index that is partitioned over three areas is
    deleted, for example, then the count will be 3. This count also
    gives the number of root node deletions.