Gregory Stark wrote:
"Gokulakannan Somasundaram" <[EMAIL PROTECTED]> writes:
a) By modifying the functions, heap_form_tuple and heap_fill_tuple, we can
check whether all the nulls are trailing nulls. If all the nulls are
trailing nulls, then we will not set the has_null flag and we will not have
the null bitmap with the tuple.
I think that would work. The only question is whether it's worth bothering
since we would have to check it on every heap_form_tuple.
This strikes me as such a corner case that it's likely not to be worth it.
If you really want to save space along these lines, one better place to
start might be mutable with column ordering - see
http://archives.postgresql.org/pgsql-hackers/2006-12/msg00983.php . That
would mean that we would be able to move nullable columns physically to
the tail which in turn might help this suggestion have more effect.
cheers
andrew
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
