So I think the case for selecting all of the columns (and for an ORM-like approach of selecting related fields at once) is to reduce the number of queries. Gene

So I think the case for selecting all of the columns (and for an ORM-like approach of selecting related fields at once) is to reduce the number of queries. Generally I think that selecting two columns at one point in application logic and firing off a separate query for another two columns later in execution of a script is going to be worse than selecting 6 columns. Query performance is not the only consideration here, you also need to consider network performance of transmitting the data from the database server to the client (although that equation might change if you're using an in-memory database or something like that). Also, selecting all the columns at once has an ergonomics effect of making it simpler to take advantage of caching when writing multiple components which might query the same data within the same execution. That being said, I do think selecting less columns is better than more, an even when using an ORM I find myself writing projects and helper objects to reduce how many columns I need in my queries, but I view that as more of an optimization, a secondary concern that I can take care of after the main logic is implemented, rather than a primary concern that should shape the initial implementation of the logic. Of course, the performance concerns I have had might be vastly different than the original poster's, so take my comment with a grain of salt.