SQLServerCentral / Discuss Content Posted by Andy Warren / Article Discussions / Article Discussions by Author / Adding a Computed Column to a Table (2) - SQL School Video / Latest PostsInstantForum.NET v2.9.0SQLServerCentralhttp://www.sqlservercentral.com/Forums/notifications@sqlservercentral.comFri, 24 May 2013 06:20:46 GMT20RE: Adding a Computed Column to a Table (2) - SQL School Videohttp://www.sqlservercentral.com/Forums/Topic735920-29-1.aspxI was wondering what the performance advantages are between a derived field in a view and computed field in a table. Would you do one over the other because one performs better?Thu, 25 Jun 2009 12:40:20 GMTPeter CroninRE: Adding a Computed Column to a Table (2) - SQL School Videohttp://www.sqlservercentral.com/Forums/Topic735920-29-1.aspxHi Andy,I'm curious to whether you'd recommend this approach for a particularly gnarly database I've inherited. It uses a concept of "partial text" for it's keys. For example, [i]2007-000123-001[/i] might be the key in a table. The first 11 characters is, in essence, the primary key of the parent table in a parent-child hierarchy. The [i]-001[/i] makes it unique in the child table and also gives it a sequential order.As you can imagine, it's painful because searches invariably rely upon substrings or LIKE clauses. I know that's killing the performance.My thought was that I could use this computed column approach to slowly migrate us out of this hell, while still maintaining legacy support. I'd be curious to hear your thoughts.Great work!-Mike LThu, 25 Jun 2009 08:56:58 GMTmikelawtonAdding a Computed Column to a Table (2) - SQL School Videohttp://www.sqlservercentral.com/Forums/Topic735920-29-1.aspxComments posted to this topic are about the item [B]<A HREF="/articles/Video/67253/">Adding a Computed Column to a Table (2) - SQL School Video</A>[/B]Tue, 16 Jun 2009 12:18:14 GMTAndy Warren