Sql Server - Index on nvarchar field
You could use CHECKSUM command and put index on column with checksum.
--*** Add extra column to your table that will hold checksumALTER TABLE Production.ProductADD cs_Pname AS CHECKSUM(Name);GO--*** Create index on new columnCREATE INDEX Pname_index ON Production.Product (cs_Pname);GOThen you can retrieve data fast using following query:
SELECT * FROM Production.ProductWHERE CHECKSUM(N'Bearing Ball') = cs_PnameAND Name = N'Bearing Ball';Here is the documentation: http://technet.microsoft.com/en-us/library/ms189788.aspx
You can use a hash function (although theoretically it doesn't guarantee that two different titles will have different hashes, but should be good enough: MD5 Collisions) and then apply the index on that column.
You could create a hash code of the url and use this integer as a unique index on your db. Beware of converting all characters to lowercase first to ensure that all url are in the same format. Same url will generate equal hash code.