Re: size of NULL field?

In article <200204151933.g3FJXT912721@candle.pha.pa.us>,
Bruce Momjian  <pgman@candle.pha.pa.us> wrote:
>Oh, I didn't realize the size of the NULL bitmask was zero if no nulls
>exist.  Nice.

So, how does the row know if the NULL bitmask exists or not?  I'm guessing
there's a structure per row somewhere that has as at least one of it's
members, a bit on whether a NULL bitmask exists or not?

If all of the members of a row become non-NULL, does the NULL bitmask go
away?

mrc

--
     Mike Castle      dalgoda@ix.netcom.com      www.netcom.com/~dalgoda/
    We are all of us living in the shadow of Manhattan.  -- Watchmen
fatal ("You are in a maze of twisty compiler features, all different"); -- gcc