\timing on

drop table big;
drop table small;

create temp table tmp_foo(i int, ir int8range);
insert into tmp_foo select g % 100, 'empty'::int8range from generate_series(1,50000) g;
insert into tmp_foo select g % 100, int8range(NULL,NULL) from generate_series(1,10000) g;
insert into tmp_foo select g % 100, int8range(NULL,((random()-0.5)*g*10)::int8) from generate_series(1,20000) g;
insert into tmp_foo select g % 100, int8range(((random()-0.5)*g*10)::int8,NULL) from generate_series(1,20000) g;
insert into tmp_foo select g % 100,
  int8range(
    (g*10 + 10*(random()-0.5))::int8,
    (g*10 + 10 + 10*(random()-0.5))::int8 )
  from generate_series(1,1000000) g;

create table big as select * from tmp_foo order by random();
drop table tmp_foo;

create table tmp_foo(i int, ir int8range);
insert into tmp_foo select g*1000 % 100, 'empty'::int8range from generate_series(1,50) g;
insert into tmp_foo select g*1000 % 100,
  int8range(
    (g*10*1000 + 10*(random()-0.5))::int8,
    (g*10*1000 + 10 + 10*(random()-0.5))::int8 )
  from generate_series(1,1000) g;

create table small as select * from tmp_foo order by random();
drop table tmp_foo;

vacuum;
vacuum;
vacuum;

create index big_idx on big using gist (ir);

analyze;

set enable_bitmapscan=false;

explain analyze select sum(upper(intersection) - lower(intersection))
from (
  select small.ir * big.ir as intersection from small,big
  where small.ir && big.ir and not lower_inf(big.ir) and not upper_inf(big.ir)
) s;

set enable_bitmapscan to default;
set enable_indexscan=false;

explain analyze select sum(upper(intersection) - lower(intersection))
from (
  select small.ir * big.ir as intersection from small,big
  where small.ir && big.ir and not lower_inf(big.ir) and not upper_inf(big.ir)
) s;

set enable_indexscan to default;