TABLE_STATISTICS Rowset

OLE DB Programmer's Reference

GUID: DBSCHEMA_TABLE_STATISTICS

Number of restriction columns: 7

Restriction columns: TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, STATISTICS_CATALOG, STATISTICS_SCHEMA, STATISTICS_NAME, STATISTICS_TYPE

Default sort order: TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, STATISTICS_CATALOG, STATISTICS_SCHEMA, STATISTICS_NAME, ORDINAL_POSITION

Description: The TABLE_STATISTICS rowset describes the available set of statistics on tables in the provider.

Note   This rowset is not related to the STATISTICS rowset. See additional information in the "Special-Purpose Rowsets" section of Chapter 1: Overview of OLE DB, and IOpenRowset::OpenRowset.

Column name	Type indicator	Description
TABLE_CATALOG	DBTYPE_WSTR	Catalog name of the table of this statistic. NULL if the provider does not support catalogs.
TABLE_SCHEMA	DBTYPE_WSTR	Schema name of the table. NULL if the provider does not support schemas.
TABLE_NAME	DBTYPE_WSTR	Table name.
STATISTICS_CATALOG	DBTYPE_WSTR	Catalog name of the statistic. NULL if the provider does not support catalogs.
STATISTICS_SCHEMA	DBTYPE_WSTR	Schema name of the statistic. NULL if the provider does not support schemas.
STATISTICS_NAME	DBTYPE_WSTR	Name of the statistic.
STATISTICS_TYPE	DBTYPE_UI2	Bit-mask specifying the kinds of statistics supported by this statistic: DBSTAT_HISTOGRAM—Indicates histogram support. DBSTAT_COLUMN_CARDINALITY— Indicates column cardinality support. DBSTAT_TUPLE_CARDINALITY—Indicates tuple cardinality support. Note    Histograms correspond to only the first column for a multi-column statistic.
COLUMN_NAME	DBTYPE_WSTR	Name of the column that is part of this statistic.
COLUMN_GUID	DBTYPE_GUID	Column GUID. Providers that do not identify columns with GUIDs should return NULL for this column.
COLUMN_PROPID	DBTYPE_UI4	Column PROPID. Providers that do not associate PROPIDs with columns should return NULL for this column.
ORDINAL_POSITION	DBTYPE_UI4	Ordinal position of the column in the statistic starting with one.
SAMPLE_PCT	DBTYPE_UI2	Percentage of the base table s rows that were sampled to produce this statistic. NULL if not supported.
LAST_UPDATE_TIME	DBTYPE_DATE	The time when this statistic was last updated. NULL if not supported.
NO_OF_RANGES	DBTYPE_UI4	Number of ranges in histogram. NULL if histograms are not supported as part of this statistic.
COLUMN_CARDINALITY	DBTYPE_I8	Number of unique values of the specified column in the table. NULL if cardinality information is not available for this column.
TUPLE_CARDINALITY	DBTYPE_I8	Number of unique values of the tuple <c1, c2, ..., ci> in the table where c1, c2, ..., ci are the columns in the statistic as indicated by ORDINAL_POSITION 1, 2, ..., i, respectively. NULL if cardinality information is not available for this tuple.
TABLE_CARDINALITY	DBTYPE_I8	Number of rows in the table.
AVG_COLUMN_LENGTH	DBTYPE_UI4	The average length in bytes of the column in the table. This is required only for variable-length character or binary columns (of types DBTYPE_WSTR, DBTYPE_STR, DBTYPE_BYTES, and DBTYPE_VARNUMERIC) and is optional for fixed-length data types. NULL if the provider does not maintain this information.

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