![]() The optimizer may consider additional columns if needed. However, you can achieve greater control over the access path used by the query optimizer by specifying both the index to seek on and the index columns to consider in the seek operation. Specifying FORCESEEK with index parameters is similar to using FORCESEEK with an INDEX hint. The name of the index column to include in the seek operation. To return the index name or ID, query the sys.indexes catalog view. The index ID 0 (heap) can't be specified. In that case, the query optimizer considers only index seek operations through the specified index using at least the specified index columns. Starting with SQL Server 2008 R2 (10.50.x) Service Pack 1, index parameters can also be specified. ![]() Specifies that the query optimizer uses only an index seek operation as the access path to the data in the table or view. ![]() SELECT * FROM OPENROWSET(BULK.) statement, see Keep Nulls or Use Default Values During Bulk Import (SQL Server). Specifies insertion of a table column's default value, if any, instead of NULL when the data record lacks a value for the column.įor an example that uses this hint in an INSERT. KEEPDEFAULTSĪpplicable only in an INSERT statement when the BULK option is used with OPENROWSET. SELECT * FROM OPENROWSET(BULK.) statement, see Keep Identity Values When Bulk Importing Data (SQL Server).įor information about checking the identity value for a table, see DBCC CHECKIDENT (Transact-SQL). If an identity column is skipped successfully, the query optimizer automatically assigns unique values for the identity column into the imported table rows.įor an example that uses this hint in an INSERT. For more information, see Use a Format File to Skip a Data Field (SQL Server). ![]() If the data file does not contain values for the identity column in the table or view, and the identity column is not the last column in the table, you must skip the identity column. If the collection of hinted indexes don't include all columns referenced by the query, a fetch is performed to retrieve the remaining columns after the SQL Server Database Engine retrieves all the indexed columns. A multiple index hint also enforces index ANDing, and the query optimizer applies as many conditions as possible on each index accessed. The order of the indexes in the index hint is significant. If multiple indexes are used in a single hint list, the duplicates are ignored, and the rest of the listed indexes are used to retrieve the rows of the table. If no clustered index exists, INDEX(0) forces a table scan, and INDEX(1) is interpreted as an error. If a clustered index exists, INDEX(0) forces a clustered index scan, and INDEX(1) forces a clustered index scan or seek. Only one index hint per table can be specified. The alternative INDEX = syntax specifies a single index value. The INDEX() syntax specifies the names or IDs of one or more indexes to be used by the query optimizer when it processes the statement. For more information, see Using NOEXPAND. The query optimizer treats the view like a table with clustered index. Specifies that any indexed views aren't expanded to access underlying tables when the query optimizer processes the query. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Separating hints by spaces rather than commas is a deprecated feature: This feature will be removed in a future version of Microsoft SQL Server. ![]() Transact-SQL syntax conventions Syntax WITH (. Because the SQL Server query optimizer typically selects the best execution plan for a query, we recommend that hints be used only as a last resort by experienced developers and database administrators. ![]()
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