Reusing Dead Tuples:

Hi,
I am doing some experiments on dead tuples, I am looking of reusing the
dead tuples apace in a particular page during the "Update".This patch
is meant for the tables
which are heavily updated to avoid vacuum very frequently.By using it
will arrest the size of
table for heavily updated table. The algorithm works like this:
1) During the update it check for the dead tuples in the current
page(page that contain
the tuple that need to be updated). If it finds any dead tuples it uses
the dead tuple space
by ovewriting on dead tuple. The checking of dead tuple is very similer
to the task that of
lazy vaccum.
2) If it cannot find any dead tuple it proceed as usual by inserting
at the end of table .

Performance Effect:
1) The CPU processing will be slighly more for the update, but io
processing is
exactly same
2) The size of table grows slower under heavy update , so vacuum is
not required very frequently.
The total processing for update is more or less same even after
doing large number of updates without vacuum.

Does it breaks anythings by overwriting the dead tuples ?.

Comments?.

jana