"Jim C. Nasby" <[EMAIL PROTECTED]> wrote: > The reason I thought of this is because once the transaction commits, we > have no use for the cid info. So we could do something like have > bgwriter look for tuples that belong to committed transactions before it > writes a page, and strip the cid out of them.
Your concept is just like as the experimental method that I suggested before in http://archives.postgresql.org/pgsql-hackers/2005-08/msg01193.php We can remove cmin and cmax from commited tuples and xmin from frozen tuples and we might save some bytes in tuple headers. However, I think our next goal to shrink the headers is 16 bytes. The headers become 23 bytes using phantom cids and we are limited by alignments, so we will have no more advantages unless we delete extra 7 bytes in the headers. ...and it seems to be very difficult. Regards, --- ITAGAKI Takahiro NTT Open Source Software Center ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
