INDEXSTATISTICS 

This statistical system table contains information about structure and size of indexes.

INDEXSTATISTICS

OWNER

CHAR ( 32)

Owner of a table

TABLENAME

CHAR ( 32)

table name

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 Column DESCRIPTION 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

FILETYPE

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 page used

Space used in root page(%)

NUMERIC_VALUE contains the percentage of the B* tree root page 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 index list

Min primary keys per list

NUMERIC_VALUE contains the minimum number of keys per index list

Max primary keys per list

NUMERIC_VALUE contains the maximum number of keys per index list

Values with selectivity <= 1%

NUMERIC_VALUE contains the number of index lists with a selectivity <= 1%

Values with selectivity <= 5%

NUMERIC_VALUE contains the number of index lists with a selectivity between 5% and 1%

Values with selectivity <= 10%

NUMERIC_VALUE contains the number of index lists with a selectivity between 10% and 5%

Values with selectivity <= 25%

NUMERIC_VALUE contains the number of index lists with a selectivity between 10% and 25%.

Values with selectivity > 25%

NUMERIC_VALUE contains the number of index lists with a selectivity > 25%