Teradata Forums / Teradata / Teradata Advanced Analytics User Group / Is there a performance hit selecting rows based upon a constructed CASE column? / Latest PostsInstantForum.NET v4.1.4Teradata Forumshttp://www.teradata.com/teradataforum/info@teradata.comFri, 05 Sep 2008 19:39:35 GMT20RE: Is there a performance hit selecting rows based upon a constructed CASE column?http://www.teradata.com/teradataforum/Topic11127-22-1.aspxHi Ti,you're right, there's no difference. Btw, if you want to lower CPU usage, stay away from conversions involving type casts from char to numeric/date and vice versa.DieterThu, 03 Apr 2008 03:11:43 GMTdnoethIs there a performance hit selecting rows based upon a constructed CASE column?http://www.teradata.com/teradataforum/Topic11127-22-1.aspxHi,Quick question. I think there is no difference, but I need to be sure.In a SELECT or INSERT statement if I use a CASE statement to create a new column and then select rows based upon the value of that new column, is it any slower (or faster) than simply repeating the logic of the CASE statement as a direct WHERE condition?I'm processing a *lot* of data with nasty string functions and I need every ounce of optimisation I can get :)ThanksTimWed, 02 Apr 2008 17:35:59 GMTTimManns