CREATE TABLE readings (
  katakana text
);

INSERT INTO readings VALUES ('ポストグレスキューエル');
INSERT INTO readings VALUES ('グルンガ');
INSERT INTO readings VALUES ('ピージールンガ');
INSERT INTO readings VALUES ('ピージーロジカル');

CREATE INDEX pgrn_index ON readings
  USING pgroonga (katakana pgroonga.text_term_search_ops_v2);

SET enable_seqscan = off;
SET enable_indexscan = off;
SET enable_bitmapscan = on;

EXPLAIN (COSTS OFF)
SELECT katakana
  FROM readings
 WHERE katakana &^~| ARRAY['po', 'gu'];

SELECT katakana
  FROM readings
 WHERE katakana &^~| ARRAY['po', 'gu'];

DROP TABLE readings;
