Re: SSI patch version 14

On Sat, 2011-02-05 at 14:43 -0600, Kevin Grittner wrote:
> "Kevin Grittner"  wrote:
>  
> > So now that I'm sure we actually do need code there, I'll add it.
>  
> In working on this I noticed the apparent need to move two calls to
> PredicateLockTuple a little bit to keep them inside the buffer lock. 
> Without at least a share lock on the buffer, it seems that here is a
> window where a read could miss the MVCC from a write and the write
> could fail to see the predicate lock.  Please see whether this seems
> reasonable:
>  
>
http://git.postgresql.org/gitweb?p=users/kgrittn/postgres.git;a=commitdiff;h=7841a22648c3f4ae46f674d7cf4a7c2673cf9ed2

What does PredicateLockTuple do that needs a share lock? Does a pin
suffice?

Regards,Jeff Davis