## INDEXSTATISTICS

### Definition

The statistics system table INDEXSTATISTICS contains information about the structure and sizes of indexes sapurl_link_0001_0001_0001.

### Structure

INDEXSTATISTICS

SCHEMANAME | CHAR(32) | Name of the schema of the table
OWNER | CHAR(32) | Name of the owner of the table
TABLENAME | CHAR(32) | Name of the table
INDEXNAME | CHAR(32) | Index name (NULL for unnamed indexes)
COLUMNNAME | CHAR(32) | Name of an inverted column
DESCRIPTION | CHAR(40) | Description of how to interpret the following columns (see DESCRIPTION Column table)
CHAR_VALUE | CHAR(12) | Alphanumeric value
NUMERIC_VALUE | FIXED(10) | Numeric value

DESCRIPTION Column

Value | Explanation
Root pno | NUMERIC_VALUE contains the page number of the B* tree root
File type | CHAR_VALUE contains the B* tree type
Used pages | NUMERIC_VALUE contains the number of pages used by the index
Index pages | NUMERIC_VALUE contains the number of B* tree index pages used by the index
Leaf pages | NUMERIC_VALUE contains the number of leaf pages used by the index
Index levels | NUMERIC_VALUE contains the number of B* tree index levels
Space used in all pages(%) | NUMERIC_VALUE contains the percentage of the B* tree root pages used
Space used in root page(%) | NUMERIC_VALUE contains the percentage of the B* tree root pages used
Space used in index pages(%) | NUMERIC_VALUE contains the percentage of the B* tree index pages used
Space used in index pages(%) min | NUMERIC_VALUE contains the minimum percentage of the B* tree index pages used
Space used in index pages(%) max | NUMERIC_VALUE contains the maximum percentage of the B* tree index pages used
Space used in leaf pages(%) | NUMERIC_VALUE contains the percentage of the B* tree leaf pages used
Space used in leaf pages(%) min | NUMERIC_VALUE contains the minimum percentage of the B* tree leaf pages used
Space used in leaf pages(%) max | NUMERIC_VALUE contains the maximum percentage of the B* tree leaf pages used
Secondary keys (index lists) | NUMERIC_VALUE contains the number of different values in the indexed columns
Avg secondary key length | NUMERIC_VALUE contains the average length of the index values
Min secondary key length | NUMERIC_VALUE contains the minimum length of the index values
Max secondary key length | NUMERIC_VALUE contains the maximum length of the index values
Avg separator length | NUMERIC_VALUE contains the average length of a B* tree separator
Min separator length | NUMERIC_VALUE contains the minimum length of the separator
Max separator length | NUMERIC_VALUE contains the maximum length of the separator
Primary keys | NUMERIC_VALUE contains the number of rows in the tables identified by OWNER and TABLENAME
Avg primary keys per list | NUMERIC_VALUE contains the average number of keys per inversion list
Min primary keys per list | NUMERIC_VALUE contains the minimum number of keys per inversion list
Max primary keys per list | NUMERIC_VALUE contains the maximum number of keys per inversion list
Values with selectivity <= 1% | NUMERIC_VALUE contains the number of inversion lists with a selectivity <= 1%
Values with selectivity <= 5% | NUMERIC_VALUE contains the number of inversion lists with a selectivity between 1% and 5%
Values with selectivity <= 10% | NUMERIC_VALUE contains the number of inversion lists with a selectivity between 5% and 10%
Values with selectivity <= 25% | NUMERIC_VALUE contains the number of inversion lists with a selectivity between 10% and 25%.
Values with selectivity > 25% | NUMERIC_VALUE contains the number of inversion lists with a selectivity > 25%

See also:

FILES

Concepts of the Database System, Logical Access Structures