From: Erland Sommarskog on
Colin (Colin(a)discussions.microsoft.com) writes:
> I have been asked to index the Timestamp column on our main source
> system database (1.3TB). The proposed index's are to help decrease the
> load time of our datawarehouse. My question is, are timestamp columns
> good candidates for indexes. (The warehouse selects between two
> timestamp values) considering the constant updates on the index this
> will cause?

Without knowing the tables involved it's hard to tell. But if this is
a table with constant updates, and many updates to the same row, it is
certainly not appealing.

But it all depends on the situation. I recently designed a table where
the primary key is a timestamp column!

If you are on SQL 2008, Change Tracking may be a better way to improve
loading of the warehouse.

In any case, it is always a tradeoff. Speed up reading in one corner,
slow down writing and create deadlocks in another.


--
Erland Sommarskog, SQL Server MVP, esquel(a)sommarskog.se

Links for SQL Server Books Online:
SQL 2008: http://msdn.microsoft.com/en-us/sqlserver/cc514207.aspx
SQL 2005: http://msdn.microsoft.com/en-us/sqlserver/bb895970.aspx
SQL 2000: http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx