text: --
  -- Test GiST indexes.
  --
  -- There are other tests to test different GiST opclasses. This is for
  -- testing GiST code itself. Vacuuming in particular.
  
  create table gist_point_tbl(id int4, p point);
  create index gist_pointidx on gist_point_tbl using gist(p);
  
  -- Insert enough data to create a tree that's a couple of levels deep.
  insert into gist_point_tbl (id, p)
  select g,        point(g*10, g*10) from generate_series(1, 10000) g;
  
  insert into gist_point_tbl (id, p)
  select g+100000, point(g*10+1, g*10+1) from generate_series(1, 10000) g;
  
  -- To test vacuum, delete some entries from all over the index.
  delete from gist_point_tbl where id % 2 = 1;
  
  -- And also delete some concentration of values. (GiST doesn't currently
  -- attempt to delete pages even when they become empty, but if it did, this
  -- would exercise it)
  delete from gist_point_tbl where id < 10000;
  
  vacuum analyze gist_point_tbl;
  
  
  --
  -- Test Index-only plans on GiST indexes
  --
  
  create table gist_tbl (b box, p point, c circle);
  
  insert into gist_tbl
  select box(point(0.05*i, 0.05*i), point(0.05*i, 0.05*i)),
         point(0.05*i, 0.05*i),
         circle(point(0.05*i, 0.05*i), 1.0)
  from generate_series(0,10000) as i;
  
  vacuum analyze gist_tbl;
  
  set enable_seqscan=off;
  set enable_bitmapscan=off;
  set enable_indexonlyscan=on;
  
  -- Test index-only scan with point opclass
  create index gist_tbl_point_index on gist_tbl using gist (p);
  
  -- check that the planner chooses an index-only scan
  explain (costs off)
  select p from gist_tbl where p <@ box(point(0,0), point(0.5, 0.5));
  
  -- execute the same
  select p from gist_tbl where p <@ box(point(0,0), point(0.5, 0.5));
  
  -- Also test an index-only knn-search
  explain (costs off)
  select p from gist_tbl where p <@ box(point(0,0), point(0.5, 0.5))
  order by p <-> point(0.2, 0.2);
  
  select p from gist_tbl where p <@ box(point(0,0), point(0.5, 0.5))
  order by p <-> point(0.2, 0.2);
  
  -- Check commuted case as well
  explain (costs off)
  select p from gist_tbl where p <@ box(point(0,0), point(0.5, 0.5))
  order by point(0.1, 0.1) <-> p;
  
  select p from gist_tbl where p <@ box(point(0,0), point(0.5, 0.5))
  order by point(0.1, 0.1) <-> p;
  
  drop index gist_tbl_point_index;
  
  -- Test index-only scan with box opclass
  create index gist_tbl_box_index on gist_tbl using gist (b);
  
  -- check that the planner chooses an index-only scan
  explain (costs off)
  select b from gist_tbl where b <@ box(point(5,5), point(6,6));
  
  -- execute the same
  select b from gist_tbl where b <@ box(point(5,5), point(6,6));
  
  drop index gist_tbl_box_index;
  
  -- Test that an index-only scan is not chosen, when the query involves the
  -- circle column (the circle opclass does not support index-only scans).
  create index gist_tbl_multi_index on gist_tbl using gist (p, c);
  
  explain (costs off)
  select p, c from gist_tbl
  where p <@ box(point(5,5), point(6, 6));
  
  -- execute the same
  select b, p from gist_tbl
  where b <@ box(point(4.5, 4.5), point(5.5, 5.5))
  and p <@ box(point(5,5), point(6, 6));
  
  drop index gist_tbl_multi_index;
  
  -- Clean up
  reset enable_seqscan;
  reset enable_bitmapscan;
  reset enable_indexonlyscan;
  
  drop table gist_tbl;
  