Bruce Momjian wrote: > > Alessio Bragadini wrote: > > On Sat, 2002-10-12 at 11:37, Gavin Sherry wrote: > > > > > I cannot think of any reason why changing column order should be > > > implemented in Postgres. Seems like a waste of time/more code bloat for > > > something which is strictly asthetic. > > > > > > Regardless, I do have collegues/clients who ask when such a feature will > > > be implemented. Why is this useful? > > > > Has column ordering any effect on the physical tuple disposition? I've > > heard discussions about keeping fixed-size fields at the beginning of > > the tuple and similar. > > > > Sorry for the lame question. :-) > > Yes, column ordering matches physical column ordering in the file, and > yes, there is a small penalty for accessing any columns after the first > variable-length column (pg_type.typlen < 0). CHAR() used to be a fixed > length column, but with TOAST (large offline storage) it became variable > length too. I don't think there is much of a performance hit, though.
When was char() fixed size? We had fixed size things like char, char2, char4 ... char16. But char() is internally bpchar() and has allways been variable-length. Jan -- #======================================================================# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #================================================== [EMAIL PROTECTED] # ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
