The statistics system table INDEXSTATISTICS contains information about the structure and sizes of indexes.
INDEXSTATISTICS
OWNER |
CHAR(32) |
Table owner |
TABLENAME |
CHAR(32) |
Table name |
INDEXNAME |
CHAR(32) |
Index name (NULL for unknown indexes) |
COLUMNNAME |
CHAR(32) |
Name of an inverted column |
DESCRIPTION |
CHAR(40) |
Description (see table Column DESCRIPTION) of how to interpret following columns |
CHAR_VALUE |
CHAR(12) |
Alphanumeric value |
NUMERIC_VALUE |
FIXED(10) |
Numeric value |
Column DESCRIPTION
Value |
Explanation |
Root pno |
NUMERIC_VALUE contains the page number of the root of the B* tree |
Filetype |
CHAR_VALUE contains the type of the B* tree |
Used pages |
NUMERIC_VALUE indicates how many pages are used by the index |
Index pages |
NUMERIC_VALUE indicates how many pages are used by the index in the B* tree index |
Leaf pages |
NUMERIC_VALUE indicates how many leaf pages are used by the index |
Index levels |
NUMERIC_VALUE contains the number of index levels in the B* tree |
Space used in all pages(%) |
NUMERIC_VALUE contains the used space of all pages in the B* tree (as a percentage) |
Space used in root page(%) |
NUMERIC_VALUE contains the used space of the root page in the B* tree (as a percentage) |
Space used in index pages(%) |
NUMERIC_VALUE contains the used space of the index pages in the B* tree (as a percentage) |
Space used in index pages(%) min |
NUMERIC_VALUE contains the minimum used space of the index pages in the B* tree (as a percentage) |
Space used in index pages(%) max |
NUMERIC_VALUE contains the maximum used space of the index pages in the B* tree (as a percentage) |
Space used in leaf pages(%) |
NUMERIC_VALUE contains the used space of the leaf pages in the B* tree (as a percentage) |
Space used in leaf pages(%) min |
NUMERIC_VALUE contains the minimum used space of the leaf pages in the B* tree (as a percentage) |
Space used in leaf pages(%) max |
NUMERIC_VALUE contains the maximum used space of the leaf pages in the B* tree (as a percentage) |
Secondary keys (index lists) |
NUMERIC_VALUE contains the number of different values of the indexed columns |
Avg secondary key length |
NUMERIC_VALUE contains the average length of an index value |
Min secondary key length |
NUMERIC_VALUE contains the minimum length of an index value |
Max secondary key length |
NUMERIC_VALUE contains the maximum length of an index value |
Avg separator length |
NUMERIC_VALUE contains the average length of a separator in the B* tree |
Min separator length |
NUMERIC_VALUE contains the minimum length of a separator |
Max separator length |
NUMERIC_VALUE contains the maximum length of a separator |
Primary keys |
NUMERIC_VALUE contains the number of rows in the table identified by OWNER and TABLENAME |
Avg primary keys per list |
NUMERIC_VALUE contains the average number of keys for each invert list |
Min primary keys per list |
NUMERIC_VALUE contains the minimum number of keys for each invert list |
Max primary keys per list |
NUMERIC_VALUE contains the maximum number of keys for each invert list |
Values with selectivity <= 1% |
NUMERIC_VALUE contains the number of invert lists with a selectivity <= 1% |
Values with selectivity <= 5% |
NUMERIC_VALUE contains the number of invert lists with a selectivity between 1% and 5% |
Values with selectivity <= 10% |
NUMERIC_VALUE contains the number of invert lists with a selectivity between 5% and 10% |
Values with selectivity <= 25% |
NUMERIC_VALUE contains the number of invert lists with a selectivity between 10% and 25% |
Values with selectivity > 25% |
NUMERIC_VALUE contains the number of invert lists with a selectivity > 25% |