Re: New FSM patch

On Thu, 2008-09-04 at 11:07 +0300, Heikki Linnakangas wrote:
> Thanks for the review!

Not as thorough as I would have liked, I must admit.

Thanks for the other confirmations.

> Scenario: The binary tree on a page is corrupt, so that the value of an 
> upper node is > Max(leftchild, rightchild).
> Consequence: Searchers will notice the corruption while trying to 
> traverse down that path, and throw an elog(WARNING) in search_avail(). 
> fsm_search will retry the search, and will in worst case go into an 
> infinite loop. That's obviously not good. We could automatically fix the 
> upper nodes of the tree, but that would wipe evidence that would be 
> useful in debugging.

We probably need to break out of infinite loops, especially ones that
output warning messages on each loop. :-)

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support