Indexing SQL Database (server 2012)

Indexes are per table not at database level. Every table should have an index, which is also a primary key(PK). Good candidates for PK are columns or groups of columns that are unique. A PK has to uniquely identify a row in a table. There are 2 main kinds of indexes in SQL server, clustered index and nonclustered index. A table can have only one clustered index, which is the index that determines the physical row order in a table and is also used as a reference by any other nonclustered index in the table. Clustered means that the index actually is the table (it is clustered with the data) and if you have other indexes they will not point directly to  a row but to the cluster index that identifies the row. You could think of nonclustered indexes as "indirect" indexes. In SQL server the PKs are by default created as clustered but they don't have to be. When it comes to what columns you want to create index on you should thing on how you will use and query the table. ALL the columns that will participate in JOIN operations have to be indexed. Foreign Keys, that is column that point to rows in related tables, usually used in joins, also have to have indexes. Columns that are frequently used in WHERE clause also need to be indexed.

This is just in a nutshell what you need to know about indexes but the subject is quite large and it takes time to fully understand.  You can start here:

https://technet.microsoft.com/en-us/library/jj835095(v=sql.110).aspx

For syntax and examples you can look here:

http://www.tutorialspoint.com/sql/sql-indexes.htm

You can also create indexes using the UI from Management Studio.

Wheew... looks like I have some research to do. Thank you!