Search & Analysis in SQL Server

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After googling i came to know that Index seek is better than scan.

How can I write the query that will yield to seek instead of scan. I am trying to find this in google but as of now no luck.

Any simple example with explanation will be appreciated.

Thanks


  1. Search by the primary key column(s)
  2. Search by column(s) with index(es) on them

An index is a data structure that improves the speed of data retrieval operations on a database table. Most dbs automatically create an index when a primary key is defined for a table. SQL Server creates an index for primary key (composite or otherwise) as a "clustered index", but it doesn't have to be the primary key - it can be other columns.

NOTE:

  • LIKE '%'+ criteria +'%' will not use an index; LIKE criteria +'%' will

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