BEGIN;
CREATE VIEW documents_view  WITH (security_barrier=true) AS 
SELECT documents.id as id,
         documents.no as no
  FROM documents WHERE ( "no"::int <= 100 AND  "no"::int > 0 )
UNION ALL   
SELECT documents.id as id,
         documents.no as no
  FROM documents WHERE ( "no"::int <= 200 AND  "no"::int > 100 )
UNION ALL   
SELECT documents.id as id,
         documents.no as no
  FROM documents WHERE ( "no"::int <= 300 AND  "no"::int > 200 )
UNION ALL   
SELECT documents.id as id,
         documents.no as no
  FROM documents WHERE ( "no"::int <= 400 AND  "no"::int > 300 )
UNION ALL   
SELECT documents.id as id,
         documents.no as no
  FROM documents WHERE ( "no"::int <= 500 AND  "no"::int > 400 )
;
----------------------------------------------
explain analyze
select * from
  documents_view
where "no"::int > 100 and "no"::int < 300;
----------------------------------------------
"Append  (cost=0.00..1780.02 rows=202 width=8) (actual time=0.049..874.701 rows=39800 loops=1)"
"  ->  Append  (cost=0.00..889.00 rows=101 width=8) (actual time=0.039..274.288 rows=20000 loops=1)"
"        ->  Seq Scan on documents  (cost=0.00..0.00 rows=1 width=28) (actual time=0.004..0.004 rows=0 loops=1)"
"              Filter: (((no)::integer <= 200) AND ((no)::integer > 100) AND ((no)::integer > 100) AND ((no)::integer < 300))"
"        ->  Seq Scan on documents_2  (cost=0.00..889.00 rows=100 width=8) (actual time=0.016..114.822 rows=20000 loops=1)"
"              Filter: (((no)::integer <= 200) AND ((no)::integer > 100) AND ((no)::integer > 100) AND ((no)::integer < 300))"
"  ->  Append  (cost=0.00..889.00 rows=101 width=8) (actual time=0.041..286.421 rows=19800 loops=1)"
"        ->  Seq Scan on documents documents_1  (cost=0.00..0.00 rows=1 width=28) (actual time=0.004..0.004 rows=0 loops=1)"
"              Filter: (((no)::integer <= 300) AND ((no)::integer > 200) AND ((no)::integer > 100) AND ((no)::integer < 300))"
"        ->  Seq Scan on documents_3  (cost=0.00..889.00 rows=100 width=8) (actual time=0.019..124.719 rows=19800 loops=1)"
"              Filter: (((no)::integer <= 300) AND ((no)::integer > 200) AND ((no)::integer > 100) AND ((no)::integer < 300))"
"              Rows Removed by Filter: 200"
"Total runtime: 1038.461 ms"