-- Short reproduction for the mail body. usage: psql -X -f repro_short.sql
\set ON_ERROR_STOP on
\pset pager off
select version();

drop table if exists orproof_t;
create table orproof_t (c int not null, a text not null, b timestamp not null, d int);
insert into orproof_t
select i % 5, 'K' || lpad(i::text, 7, '0'), timestamp '2026-01-01' + (i % 10) * interval '1 day', i
from generate_series(1, 500000) i;
create index orproof_t_c_a_b on orproof_t (c, a, b);
vacuum analyze orproof_t;

-- Builds "c = 1 AND (a, b) IN (<n entries>)"; every entry of the list exists in the table with c = 1.
create or replace function orproof_q(n int) returns text language sql as $$
  select 'explain (costs off, summary on) select * from orproof_t where c = 1 and (a, b) in ('
         || string_agg(format('(%L,%L)', 'K' || lpad((5 * k + 1)::text, 7, '0'),
                              timestamp '2026-01-01' + ((5 * k + 1) % 10) * interval '1 day'), ',')
         || ')'
    from generate_series(1, n) k
$$;

-- Prints only the top plan node and the planning time.
create or replace function orproof_plan(n int) returns setof text language plpgsql as $$
declare
  l text;
  first boolean := true;
begin
  for l in execute orproof_q(n) loop
    if first or l like 'Planning Time:%' then
      return next format('n = %s: %s', n, l);
    end if;
    first := false;
  end loop;
end $$;

select orproof_plan(n) from unnest(array[250, 500, 1000, 2000, 4000]) n;
set enable_bitmapscan = off;
select orproof_plan(n) from unnest(array[250, 500, 1000, 2000, 4000]) n;
reset enable_bitmapscan;

drop function orproof_plan(int);
drop function orproof_q(int);
drop table orproof_t;