What is entity and indexing in sqlserver

Question

Dear Sir. 1. Difference between Cluster Index and NonCluster Index? 2. What is an Entity in Sql server? 3. What is the sql server profile and use?

Datta Kharad · Answer

Hi Clustered Index:- A clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages. Nonclustered Index:- A nonclustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk. The leaf node of a nonclustered index does not consist of the data pages. Instead the leaf nodes contain index rows. See this article fot more details: http://www.mssqlcity.com/Articles/Tuning/IndexOptimTips.htm

Satyapriya Nayak · Answer

Hi Manuel Difference between Cluster Index and NonCluster Index The difference is that Clustered index is unique for any given table and we can have only one clustered index on a table. The leaf level of a clustered index is the actual data and the data is resorted in case of clustered index. Whereas in case of non-clustered index the leaf level is actually a pointer to the data in rows so we can have as many non-clustered indexes For rest two refer the below links http://www.informit.com/guides/content.aspx?g=sqlserver&seqNum=62 http://www.codeproject.com/KB/dotnet/SQLServerProfiler.aspx Thanks

Monika Arora · Answer

Hi manuel refer the following links: http://www.sql-server-performance.com/2004/index-data-structures/ http://searchsqlserver.techtarget.com/definition/entity-relationship-model http://msdn.microsoft.com/en-us/library/ms187929.aspx