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Indexes Advantage OLE DB Provider (for ADO) |
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Indexes Advantage OLE DB Provider (for ADO) |
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The Advantage OLE DB Provider supports integrated indexes in the IOpenRowset, IRowsetIndex, and IRowsetCurrentIndex interfaces.
Note SetRange is not currently exposed in ADO.
Index Properties
The Advantage OLE DB Provider implements the following properties in the DBPROPSET_INDEX property set. All of these properties are in the Index property group.
Property ID |
Description |
DBPROP_INDEX_AUTOUPDATE |
Type: VT_BOOL Typical R/W: Read-only Description: Auto Update Specifies whether the index is maintained automatically when changes are made to the corresponding base table. For the Advantage OLE DB Provider, the value is always VARIANT_TRUE, which indicates that the index is automatically maintained. |
DBPROP_INDEX_CLUSTERED |
Type: VT_BOOL Typical R/W: Read-only Description: Clustered Specifies whether an index is clustered. For the Advantage OLE DB Provider, the value is always VARIANT_FALSE, which indicates that the leaf nodes of the index contain bookmarks relating to the base table rows whose key values match the key values of the index entry. |
DBPROP_INDEX_FILLFACTOR |
Type: VT_BSTR Typical R/W: Read-only Description: Fill Factor For a B+- tree index, this property represents the storage use of page nodes during the creation of the index. The value is an integer, from 1 to 100, that represents the percentage of use of an index node. This value is always 100 in the Advantage OLE DB Provider. |
DBPROP_INDEX_NULLCOLLATION |
Type: VT_I4 Typical R/W: Read-only Description: NULL Collation Specifies how null values are collated in the index. For the Advantage OLE DB Provider, the value is always DBPROPVAL_NC_LOW, which indicates that null values are collated at the low end of the list. |
DBPROP_INDEX_NULLS |
Type: VT_I4 Typical R/W: Read-only Description: NULL Keys Specifies whether null keys are allowed. For the Advantage OLE DB Provider, the value is always DBPROPVAL_IN_ALLOWNULL, which indicates that the index allows entries where the key columns are NULL. |
DBPROP_INDEX_PRIMARYKEY |
Type: VT_BOOL Typical R/W: Read-only Description: Primary Key Specifies whether the index represents the primary key on the table. For the Advantage OLE DB Provider, this value is always VARIANT_FALSE because primary keys are not directly supported. |
DBPROP_INDEX_SORTBOOKMARKS |
Type: VT_BOOL Typical R/W: Read-only Description: Sort Bookmarks Specifies how the index treats repeated keys. For the Advantage OLE DB Provider, the value is always VARIANT_TRUE, which indicates that the index sorts repeated keys by bookmark. |
DBPROP_INDEX_TEMPINDEX |
Type: VT_BOOL Typical R/W: Read-only Description: Temporary Index Specifies whether the index is temporary. If the index is a temporary index, the value is VARIANT_TRUE. If the index is permanent, the value is VARIANT_FALSE. |
DBPROP_INDEX_TYPE |
Type: VT_I4 Typical R/W: Read-only Description: Index Type Specifies the type of the index. For the Advantage OLE DB Provider, the value is always DBPROPVAL_IT_BTREE, which indicates that the index is a B+ tree. |
DBPROP_INDEX_UNIQUE |
Type: VT_BOOL Typical R/W: Read-only Description: Unique Specifies whether index keys must be unique. If the keys in the index are unique, this value is VARIANT_TRUE. If the keys in the index are not unique, this value is VARIANT_FALSE. |