In looking at the various table indexes in the AdventureWorks2008 sample database, I noticed that all the index names are prefixed with either "PK_", "FK_", "AK_", or "IX_".  I know that the initials for the first three acronyms are for Primary Key, Foreign Key, and Alternate Key, respectively, but I have no idea what "IX" stands for.

Can someone kindly shed some light on the "IX" prefix, and where I can read more about it in the SQL Server 2008 Books Online?  Thanks.

Naom,

What is a "regular" index?  Is there a page in the SQL Server 2008 Books Online that you can refer me to?  I have looked all over and cannot seem to find what "IX" stand for, even though Microsoft frequently uses that prefix in the naming of Indexes in many of their SQL Server examples.

Thanks.

Well, indexes are indexes :-) This is the object/data structure which increases performance of the operations against data. Read here: http://msdn.microsoft.com/en-us/library/ms191195.aspx

As the side note, Primary Key and Alternative Key are logical concepta. Index is physical concept. Primary keys are implemented as unique physical indexes. Alternative keys could be defined as unique constraint (another logical concept) which physically implemented as unique physical index.

Speaking of the index structure in SQL Server, you can check: http://aboutsqlserver.com/2010/09/22/indexes-structure/

IX is used for the Index which is used to improve performance of a query. IX is just a convention for naming such indexes (not an index of some special type).

Here is a very interesting blog about indexes Little known facts about indexes

and you can also check other blogs on this topic referenced at the top of

Dmitri,

Thanks for the additional info and the hyperlinks.  In looking through all the table indexes in the sample AdventureWorks 2008 database, I was curious as to why Microsoft designated a few of them with the "IX_" prefix, while the majority of the indexes were prefixed with either "PK_", "FK_", or "AK_" (which is what I would have expected). Hence, the reason for my original question.

And while I know that "PK", "FK", and "AK" stand for Primary Key, Foreign Key, and Alternate Key, respectively, do you know what "IX" stands for?

Thanks again.

Naomi,

Thanks for the additional clarification on "IX". I was hoping that it actually stood for something, and that there was a specific reason why Microsoft used it in a few of the tables in the sample AdventureWorks 2008 database (e.g., Address, CountryRegionCurrency, Employee, SalesOrderDetail, etc.).

Oh well . . .

Hi All,

       Any good Microsoft recommended index naming standard sql server. as follows,

PK_   for primary keys
UK_   for unique keys
IX_   for non clustered non unique indexes
UX_   for unique indexes
FK_   for foreign keys
CIX_ for Clustered Index
? for Include Index
? for filter Index

Thanks