Поделиться через

DMSCHEMA_MINING_COLUMNS Rowset

  • Статья

Изменения: 14 апреля 2006 г.

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.

Change History

Release History

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

См. также

Справочник

Data Mining Schema Rowsets

Справка и поддержка

Получение помощи по SQL Server 2005