Open Minded (9/6/2010)
I got the answer right, after a long series of wrongs.Hugo Kornelis (9/6/2010)
Good question!1. FROM clause. Build an intermediate set as a copy of the single table in the FROM clause, or as the result of joining the multiple tables. Or supply a single-row result set with no columns if no FROM is specified.
Whoa!! Hugo, I always thought this behavior was from Visual Foxpro, to copy the entire table first before selecting the data.
I always thought in SQL, the data was Selected first before Where and Group, etc. Is
Just remember, the description I gave is for the logical processing order. Actual processing order is always different - the optimizer picks the "best" plan to get the results. Making a competely redundant copy of a table will never be included in that plan!