Fixes;

Fixes;

 Postgres is not able to cluster a relation on which an rtree index is
 defined. Postmaster gives the following error message:

 Too Large Allocation Request("!(0 < (size) && (size) <= (0xfffffff)):size=0
 [0x0]", File:"/export/home/postgres/src/backend/utils/mmgr/mcxt.c", Line: 220)
  !(0 <(size) && (size) <= (0xfffffff)) (0) [No such file or directory]

Submitted by: Dirk Koeser <koeser@informatik.uni-rostock.de>