On Thu, 29 Nov 2018 at 07:06, Peter Eisentraut <peter.eisentr...@2ndquadrant.com> wrote: > > That last sentence about the dropped columns is confusing to me: > > + <para> > + Columns which have been dropped from the table also contribute to the > + maximum column limit, although the dropped column values for newly > + created tuples are internally marked as NULL in the tuple's null > bitmap, > + which does occupy space. > + </para> > > So the dropped columns matter, but they are null, but the nulls matter > too. What are we really trying to say here? Maybe this: > > Columns which have been dropped from the table also contribute to the > maximum column limit. Moreover, although the dropped column values for > newly created tuples are internally marked as NULL in the tuple's null > bitmap, the null bitmap also occupies space.
I'd say that's a small improvement that's worth making. I've attached a patch using your reformed version of that paragraph. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
v6-0001-Add-documentation-section-appendix-detailing-some.patch
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