negora wrote: > According to how I understood the process, the engine would get the > name from the student with ID 1 and would look for the name of the > father with ID 1 in the hashed table. It'd do exactly the same with the > student #2 and father #2. But my big doubt is about the 3rd one > (Anthony). Would the engine "know" that it already had retrieved the > father's name for the student 1 and would avoid searching for it into > the hashed table (using some kind of internal mechanism which allows to > "re-utilize" the name)? Or would it search into the hashed table again?<br> The hash table is searched again. But that's fast, because it's a hash table. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance