Re: BTree vacuum before page splitting

Junji TERAMOTO <teramoto(dot)junji(at)lab(dot)ntt(dot)co(dot)jp> writes:
> This patch adds a function to remove unnecessary items before split
> page of BTree.

> When a new item is put in the page, it looks for the "LP_DELETE" item,
> and removes that item.

I think this is quite likely to break things :-(. What sort of
conditions have you tested it under? (If this were safe, we'd
not have invented the LP_DELETE flag to begin with, but just have
deleted known-dead items immediately.)

BTW, a patch that makes major changes in the behavior of a function
and doesn't update the code comments is unacceptable. The comments
are as important as the code, if not more so, because other people
are going to have to read this after you.

regards, tom lane