Re: Proposal for Null Bitmap Optimization(for Trailing NULLs) - Mailing list pgsql-hackers

On Mon, 2007-12-17 at 13:10 +0530, Gokulakannan Somasundaram wrote:

>     Currently we check for the existence of NULL values in the tuple
> and we set the has_null flag. If the has_null flag is present, the
> tuple will be storing a null bitmap. What i propose is

Will this work for ALTER TABLE when adding and dropping columns?

Another idea is to store the bitmap from the first nullable column.

Some of these ideas have been discussed before, so I would check the
archives thoroughly. Most everything has if you look closely enough.

--  Simon Riggs 2ndQuadrant  http://www.2ndQuadrant.com