This article describes an approach for SQL server index optimization to increase query performance.
SQL Server 2005 has a new feature to create indexes that surpass these limits called "included columns". new_index_name The new name for the index. The syntax for renaming an index in SQL Server (Transact-SQL) is: sp_rename 'table_name.old_index_name', 'new_index_name', 'INDEX'; table_name The name of the table where the index has been created.
Example 1 : SQL Server using default index . SQL Server query optimizer decides which index to use, when a query is requested. DBA can direct SQL Server which index to be used to execute query. Instead, an index provides the gateway between the table rows and query engine, in order to achieve better both database and query performance. SQL Server makes uses Index which has lowest cost based on performance. An index is a copy of information from a table that speeds up retrieval of rows from the table or view. There are some instances when Database Developer is best judge of the index used. The index itself is stored on pages, making up the Index Pages in SQL Server. … When all of the required columns are part of the index, it is called a "covering index".
SQL Server Index Variations SQL Server Index Included Columns.
USE AdventureWorks GO SELECT * FROM Person.Contact GO. An index key can contain up to 16 columns and can be up to 900 bytes wide. Adding indexes to the SQL temp tables will enhance its performance if the index is chosen correctly, otherwise, it can cause performance degradation. Not really a type of index but it's actually a clause that can be added to a non-clustered index which stores the column values listed in the clause in the leaf nodes of the index. a Persistent SQL Server temp table which is named starting with a TempDB prefix such as TempDB.DBO ... it is better to explicitly define a clustered or non-clustered index that could be configured as a non-unique index. SQL Server indexes overview Just like a book index, SQL Server index has a similar purpose, to provide faster searching, gathering and sorting of information from a database, without need to go through all of the objects over and over. A SQL Server index is no different: it is an ordered list of values and for each value there are pointers to the data pages where these values are located. SQL Server optimizer is a cost based optimizer so it picks the index which has low cost based on performance. Figure 5: Using a covering index. Example sp_rename 'contacts.contacts_idx', 'contacts_index_cname', 'INDEX… Index which is the best for performance is automatically used. old_index_name The name of the index that you wish to rename.