1  –  node_insertions_field

    This field gives the number of index entries inserted into all
    index nodes. This number includes root, leaf, and duplicate
    entries within user- and system-defined indexes.

    This number is greater than the number of records being stored
    in the database because it usually takes one to two insertions
    into an index for each record for each index. The calculation of
    node insertions minus the sum of the root, leaf, and duplicate
    insertions yields the number of entries inserted into mid-level
    nodes. This number and the "root insertions" field indicate
    sorted balancing activity.

2  –  _root_insertions_field

    This field gives the number of entries inserted into the root
    (top-level) index nodes. The number of insertions should be small
    except for when you load the database. Also, if an index consists
    of only one node, insertions into this node are not included in
    this field, but are included in the "leaf insertions" field.

3  –  _leaf_insertions_field

    This field gives the number of unique keys inserted into the
    database's indexes. This field indicates the number of entries
    inserted into the leaf (bottom-level) index nodes.

4  –  _dup__insertions_field

    This field gives the number of duplicate index keys inserted
    into the database's indexes. There should be a one-to-one
    correspondence to the number of duplicate records being stored
    in the tables.

5  –  node_creations_field

    This field gives the total number of index nodes created during
    insertion of index entries into the index trees. This includes
    root, leaf, and duplicate nodes created within user- and system-
    defined indexes. Nodes are created three ways:

    o  When an index is first defined

    o  When a node cannot accommodate an insertion, causing it to
       overflow into a new node (node splitting)

    o  When the first duplicate for a particular key is inserted into
       an index, causing a duplicate node to be created

    The total number of nodes created and the associated fields
    should be relatively small, except for an initial load of the
    database with indexes already defined, or for creation of indexes
    on already-stored data.

6  –  _root_splits_field

    This field gives the number of times the root nodes have split
    because they overflowed after an insertion. A root node split
    causes the index to grow by one level-a parent node must be
    created to point to the two "halves" of the overflowed root node.
    Therefore, two nodes are created-the parent node and the node for
    the second half of the root node. Increasing the number of tree
    levels means Oracle Rdb must search more index nodes to access a
    data row; this can result in additional I/O operations.

7  –  _leaf_creations_field

    This field gives the number of times a leaf (bottom level) node
    was created because an existing leaf node had become full and
    needed to accommodate another unique index key entry.

8  –  _dup__creations_field

    This field gives the number of times a duplicate node was created
    to accommodate more duplicated entries within the duplicate index
    node or on the first store of a duplicate key entry.

9  –  index_creations_field

    This field gives the number of times an index was created on
    a particular table. This count is the number of CREATE INDEX
    statements. Also, if an index is partitioned over three areas,
    for example, there will be a count of three index creations.