|
Column Name
|
Column Number
|
Data Type
|
Description
|
|---|---|---|---|
|
TABLE_CAT
|
1
|
NVARCHAR1
|
Catalog name
|
|
TABLE_SCHEM
|
2
|
NVARCHAR
|
Schema name
Null is returned if
the schema is not applicable to the data source. If a driver supports
schemas for some tables but not for others, such as when the driver
retrieves data from different DBMSs, it returns an empty string ("")
for those tables that do not have schemas.
|
|
TABLE_NAME
|
3
|
NVARCHAR1
|
Table name
|
|
COLUMN_NAME
|
4
|
NVARCHAR1
|
Column name
The driver returns an
empty string for a column that does not have a name.
|
|
TYPE
|
5
|
unsigned INTEGER1
|
Type of information
being returned:
TKTS_COL_STAT indicates
a statistic for the columns specified in the CARDINALITY and HISTOGRAM
columns.
|
|
CARDINALITY
|
6
|
unsigned INTEGER
|
Cardinality of column
or column set in table.
This is the number of
distinct, non-null values in the column or column set. Null is returned
if the value is not available from the data source.
|
|
NULL_FRAC
|
7
|
DOUBLE
|
Fraction (expressed
as a decimal) of the column's entries that are null.
If any of the columns
in a set of columns is null, then that entry is considered null.
|
|
MOST_COMMON_VALS
|
8
|
NVARCHAR
|
Contains a value that
is common for this column.
Null if there are no
common values.
Null if the number of
columns is greater than one.
|
|
MOST_COMMON_FREQS
|
9
|
DOUBLE
|
A frequency of the common
value returned in MOST_COMMON_VALS.
This would likely be
the number of occurrences of that particular column value divided
by the total number of rows in the table.
Null if the number of
columns is greater than one.
|
|
HISTOGRAM_ENTRY
|
10
|
unsigned INTEGER
|
The entry for the HISTOGRAM_BOUNDS
value.
Null if the number of
columns is greater than one.
|
|
HISTOGRAM_BOUNDS
|
11
|
NVARCHAR
|
One entry in a list
of values that divide the column's values into groups of approximately
equal population.
The most common values
(returned by MOST_COMMON_VALS ) are omitted from the histogram calculation.
No HISTOGRAM_BOUNDS are returned if the column's data type does
not have a less than (< ) operator, or if the values returned by
MOST_COMMON_VALS account for the entire population of the column.
Null if the number of
columns is greater than one.
|
|
CORRELATION
|
12
|
DOUBLE
|
Statistical correlation
between the physical row ordering and the logical ordering of the
column values.
The values range from
-1 to +1. This value is not returned if the column's data type
does not have a less than (< ) operator.
Null if the number of
columns is greater than one.
|
| 1Value cannot be a null or missing value | |||