Re: Fix mdsync never-ending loop problem

While skimming over this I was baffled a bit about the usage of
(InvalidBlockNumber - 1) as value for FORGET_DATABASE_FSYNC.  It took me
a while to realize that this code is abusing the BlockNumber typedef to
pass around *segment* numbers, so the useful range is much smaller and
thus the usage of that value is not a problem in practice.

I wonder if it wouldn't be better to clean this up by creating a
separate typedef for segment numbers, with its own special values?

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.