Log Message:
-----------
Modify tidbitmap.c to avoid creating a hash table until there is more
than one heap page represented in the bitmap. This is a bit ugly but
it cuts overhead fairly effectively in simple join cases. Per example
from Sergey Koposov.
Modified Files:
--------------
pgsql/src/backend/nodes:
tidbitmap.c (r1.2 -> r1.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/tidbitmap.c.diff?r1=1.2&r2=1.3)