2010年6月2日 · An index is used to speed up the performance of queries. It does this by reducing the number of database data pages that have to be visited/scanned. In SQL Server, a clustered index determines the physical order of data in a table. There can be only one clustered index per table (the clustered index IS the table). All other indexes on a table are termed non-clustered. …

2011年7月6日 · Lets say in the employee table, I have created an index (idx_name) on the emp_name column of the table. Do I need to explicitly specify the index name in select clause or it will automatically used to speed up queries. If it is required to be specified in the select clause, What is the syntax for using index in select query ?

I've created composite indexes (indices for you mathematical folk) on tables before with an assumption of how they worked. I was just curious if my assumption is correct or not. I assume that when...

2009年9月11日 · If I have the name of an index, what query can I use to find what table the index belongs to?

Given an email address column, I need to find the position of the @ sign for substringing. What is the indexof function, for strings in T-SQL? Looking for something that returns the position of a

2012年8月16日 · An index is good for picking a fraction of the rows from a table. Querying by a primary key value is the best utilization of an index. The worst scenario is accessing all rows from a table via an index, because it has to read index pages and referenced data pages. Another example is that an in-memory sort of a result set might be faster than sorting a result set via an …

I have inserted records into a SQL Server database table. The table had a primary key defined and the auto increment identity seed is set to “Yes”. This is done primarily because in SQL Azure, each...

2010年6月16日 · Would the best index to put on this table for SQL Server 2008 be an index which includes both columns in the index, or should I put a separate index on each column?

Is there going to be much benefit in indexing a boolean field in a database table? Given a common situation, like "soft-delete" records which are flagged as inactive, and hence most queries

Given that indexing is so important as your data set increases in size, can someone explain how indexing works at a database-agnostic level? For information on queries to index a field, check out ...