I can't remember the source, but I recall reading that you should not use columns that are mostly null or have very few unique values (low cardinality). In those instances, you would create a separate table that contains only those records, just as you mentioned.
If you create a separate table, just for featured articles, you can query that table w/o much performance penalty. If you have the correct indexes on both tables, you should also be fine. On the other hand, you would then have to maintain data in two, or more, tables rather than one. How many articles, in total, do you expect to have? I can't imagine a problem unless you are dealing with tens of thousands of records. If you have hundreds of thousands of records, and performance sucks, then you could create a duplicate articles table that contains ONLY featured articles, in full. An administrator would perform an action that would copy an article's entire record to the featured table. When an article is no longer featured, the record would be removed from the featured table. Of course, you would need to consider any modifications to a featured article. You would need to update in both tables. A trigger would make this process relatively simple. M!ke -----Original Message----- From: Aaron Roberson [mailto:[EMAIL PROTECTED] Sent: Tuesday, October 09, 2007 8:01 PM To: CF-Talk Subject: Help with DB design delimma Hey all, Here is my simple use case: I have a table of articles. I would like to indicates some as featured. Here is my dilemma: Since only a few rows in the table will be featured articles I figured it would be bad to have an "isfeatured" field in the table. Why have a field for every row when a small minority will actually use it? My thought was to create a second table with all of the featured article id's. However, should I really create a table with one field just for maintaining a list of article id's? What would be the "best" approach? Thanks, Aaron ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| ColdFusion 8 - Build next generation apps today, with easy PDF and Ajax features - download now http://download.macromedia.com/pub/labs/coldfusion/cf8_beta_whatsnew_052907.pdf Archive: http://www.houseoffusion.com/groups/CF-Talk/message.cfm/messageid:290714 Subscription: http://www.houseoffusion.com/groups/CF-Talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4
