INDEXSTATISTICS

Definition

The statistics system table INDEXSTATISTICS contains information about the structure and sizes of indexessapurl_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