What is entity and indexing in sqlserver

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

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

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