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DMSCHEMA_MINING_COLUMNS Rowset

  • Artikkeli

Describes the individual columns of all data mining models in Microsoft SQL Server 2005 Analysis Services (SSAS). This rowset is restricted to the current catalog.

Rowset Columns

The DMSCHEMA_MINING_COLUMNS rowset contains the following columns.

Column name Type indicator Length Description

MODEL_CATALOG

DBTYPE_WSTR

The catalog name. Populated with the name of the database of which the model is a member.

MODEL_SCHEMA

DBTYPE_WSTR

The unqualified schema name. This column is not supported by Microsoft SQL Server 2005 Analysis Services (SSAS); it always contains NULL.

MODEL_NAME

DBTYPE_WSTR

The mining model name. This column contains the name of the mining model with which a column is associated, and it is never empty.

COLUMN_NAME

DBTYPE_WSTR

The name of the column.

COLUMN_GUID

DBTYPE_GUID

The column GUID. This column is not supported by Analysis Services; it always contains NULL.

COLUMN_PROPID

DBTYPE_UI4

The column property ID. This column is not supported by Analysis Services; it always contains NULL.

ORDINAL_POSITION

DBTYPE_UI4

The ordinal position of the column. Columns are numbered starting from 1. This column contains NULL if there is no stable ordinal value for the column.

COLUMN_HAS_DEFAULT

DBTYPE_BOOL

A Boolean that indicates whether the column has a default value.

TRUE if the column has a default value, otherwise FALSE.

COLUMN_DEFAULT

DBTYPE_WSTR

The default value of the column.

If the default value is the NULL value, COLUMN_HASDEFAULT contains TRUE, and this column contains NULL.

COLUMN_FLAGS

DBTYPE_UI4

A bitmask that describes characteristics of the column. The DBCOLUMNFLAGS enumerated type specifies the bits in the bitmask. This column is never empty.

IS_NULLABLE

DBTYPE_BOOL

A Boolean that indicates whether the column is nullable.

FALSE if the column is known not to be nullable; otherwise, TRUE.

DATA_TYPE

DBTYPE_UI2

The indicator of the column's data type. The following list shows examples of the types of indicator returned:

"TABLE" would return DBTYPE_HCHAPTER.

"TEXT" would return DBTYPE_WCHAR.

"LONG" would return DBTYPE_I8.

"DOUBLE" would return DBTYPE_R8.

"DATE" would return DBTYPE_DATE.

TYPE_GUID

DBTYPE_GUID

The GUID of the column's data type. This column is not supported by Analysis Services; it always contains VT_NULL.

CHARACTER_MAXIMUM_LENGTH

DBTYPE_UI4

The maximum possible length of a value in the column. For character, binary, or bit columns, this is one of the following:

  • The maximum length of the column in characters, bytes, or bits, respective to the column type, if a length is defined. For example, a CHAR(5) column in an SQL table has a maximum length of 5.
  • The maximum length of the data type in characters, bytes, or bits, respective to the column type, if the column does not have a defined length.
  • Zero (0) if neither the column nor the data type has a defined maximum length.
  • NULL for all other types of columns

CHARACTER_OCTET_LENGTH

DBTYPE_UI4

The maximum length in octets (bytes) of the column, if the type of the column is character or binary. A value of zero (0) means the column has no maximum length. This column contains NULL for all other types of columns.

NUMERIC_PRECISION

DBTYPE_UI2

The maximum precision of the column if the column's data type is of a numeric data type other than VARNUMERIC.

NULL if the column's data type is not numeric or is VARNUMERIC.

The precision of columns with a data type of DBTYPE_DECIMAL or DBTYPE_NUMERIC depends on the column definition.

NUMERIC_SCALE

DBTYPE_I2

The number of digits to the right of the decimal point if the column's type indicator is DBTYPE_DECIMAL, DBTYPE_NUMERIC, or DBTYPE_VARNUMERIC. Otherwise, this column contains VT_NULL.

DATETIME_PRECISION

DBTYPE_UI4

The date/time precision (number of digits in the fractional seconds portion) of the column if the column data type is a DateTime or interval type; otherwise, NULL.

CHARACTER_SET_CATALOG

DBTYPE_WSTR

The catalog name in which the character set is defined. This column is not supported by Analysis Services; it always contains NULL.

CHARACTER_SET_SCHEMA

DBTYPE_WSTR

An unqualified schema name in which the character set is defined. This column is not supported by Analysis Services; it always contains NULL.

CHARACTER_SET_NAME

DBTYPE_WSTR

The character set name. This column is not supported by Analysis Services; it always contains NULL.

COLLATION_CATALOG

DBTYPE_WSTR

The catalog name in which the collation is defined. This column is not supported by Analysis Services; it always contains NULL.

COLLATION_SCHEMA

DBTYPE_WSTR

An unqualified schema name in which the collation is defined. This column is not supported by Analysis Services; it always contains NULL.

COLLATION_NAME

DBTYPE_WSTR

The collation name. This column is not supported by Analysis Services; it always contains NULL.

DOMAIN_CATALOG

DBTYPE_WSTR

The catalog name in which the domain is defined. This column is not supported by Analysis Services; it always contains NULL.

DOMAIN_SCHEMA

DBTYPE_WSTR

The unqualified schema name in which the domain is defined. This column is not supported by Analysis Services; it always contains NULL.

DOMAIN_NAME

DBTYPE_WSTR

The domain name. This column is not supported by Analysis Services; it always contains NULL.

DESCRIPTION

DBTYPE_WSTR

A user-friendly description of the column This column is not supported by Analysis Services; it always contains NULL.

DISTRIBUTION_FLAG

DBTYPE_WSTR

A description of the statistical distribution of the column. This column contains one of the following:

  • "NORMAL"
  • "LOG_NORMAL"
  • "UNIFORM"

CONTENT_TYPE

DBTYPE_WSTR

A description of the content of the column. This column contains one of the following:

  • "KEY"
  • "DISCRETE"
  • "CONTINUOUS"
  • "DISCRETIZED([arguments])"
  • "ORDERED"
  • "KEY TIME"
  • "CYCLICAL"
  • "PROBABILITY"
  • "VARIANCE"
  • "STDEV"
  • "SUPPORT"
  • "PROBABILITY_VARIANCE"
  • "PROBABILITY_STDEV"
  • "KEY SEQUENCE"

MODELING_FLAG

DBTYPE_WSTR

A comma-delimited list of flags. The defined flags are:

  • "MODEL_EXISTENCE_ONLY"
  • "REGRESSOR"

Algorithm-specific modeling flags can also be contained in this column.

IS_RELATED_TO_KEY

DBTYPE_BOOL

A Boolean that indicates whether the column is related to the key.

TRUE if this column is related to the key. If the key is a single column, the RELATED_ATTRIBUTE field can optionally contain its column name.

RELATED_ATTRIBUTE

DBTYPE_WSTR

The name of the target column to which the current column either relates or is a special property.

IS_INPUT

DBTYPE_BOOL

A Boolean that indicates whether the column is an input column.

VARIANT_TRUE if this is an input column.

IS_PREDICTABLE

DBTYPE_BOOL

A Boolean that indicates whether the column is predictable.

TRUE if the column is predictable.

CONTAINING_COLUMN

DBTYPE_WSTR

The name of the TABLE column that contains this column. This column contains NULL if the column is not contained in another column.

PREDICTION_SCALAR_FUNCTIONS

DBTYPE_WSTR

A comma-delimited list of scalar functions that can be performed on the column.

PREDICTION_TABLE_FUNCTIONS

DBTYPE_WSTR

A comma-delimited list of functions that can be applied to the column. The functions should return a table. The list has the following format:

<function name>(<column1> [, <column2>], ...)

The format allows the client application to determine the signature (list of parameters) for the respective function.

IS_POPULATED

DBTYPE_BOOL

A Boolean that indicates whether the column has been trained with a set of possible values.

TRUE if the column has been trained with a set of possible values.

Contains FALSE if the column is not populated.

PREDICTION_SCORE

DBTYPE_R8

The score of the model on predicting the column. Score is used to measure the accuracy of a model.

SOURCE_COLUMN

DBTYPE_WSTR

The name of the source mining structure column for the current mining column.

Restriction Columns

The DMSCHEMA_MINING_COLUMNS rowset can be restricted on the columns listed in the following table.

Column name Type indicator Restriction State

MODEL_CATALOG

DBTYPE_WSTR

Optional.

MODEL_SCHEMA

DBTYPE_WSTR

Optional.

MODEL_NAME

DBTYPE_WSTR

Optional.

COLUMN_NAME

DBTYPE_WSTR

Optional.

See Also

Reference

Data Mining Schema Rowsets

Help and Information

Getting SQL Server 2005 Assistance

Change History

Release History

14 April 2006
Changed content:
  • Updated technical information in many of the column descriptions.