TABLE_STATISTICS Rowset
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 Special-Purpose Rowsets 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. |