Under the hood of views - Mailing list pgsql-performance

 developer came by and asked me an interesting question.

If he has a view with 20 columns in it, and he selects a specific column from the view
in his query. Does the engine when accessing the view return all columns? or is it
smart enough to know to just retrive the one?

example:

create view test as
select a,b,c,d,e,f,g from testtable;


select a from test;

(does the engine retrieve b-g?)

Thanks

Dave