pg_locks documentation vs. SSI

While taking a look at the existing documentation for pg_locks I came
across the following paragraph:
 <para>  When the <structname>pg_locks</structname> view is accessed, the  internal lock manager data structures are
momentarilylocked, and  a copy is made for the view to display.  This ensures that the  view produces a consistent set
ofresults, while not blocking  normal lock manager operations longer than necessary.  Nonetheless  there could be some
impacton database performance if this view is  frequently accessed. </para>
 

AFAICS, this is no longer quite true.  The view of the data from the
main lock manager will be self-consistent, and the view of the data
from the predicate lock manager will be self-consistent, but they need
not be consistent with each other.  I don't think that's a problem we
need to fix, but we probably ought to make the documentation match the
behavior.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company