text: CREATE TABLE tags (
    names text[]
  );
  
  INSERT INTO tags VALUES (ARRAY['PostgreSQL', 'PG']);
  INSERT INTO tags VALUES (ARRAY['Groonga', 'grn']);
  INSERT INTO tags VALUES (ARRAY['PGroonga', 'pgrn']);
  
  CREATE INDEX pgrn_index ON tags
    USING pgroonga (names pgroonga_text_array_term_search_ops_v2);
  
  SET enable_seqscan = off;
  SET enable_indexscan = on;
  SET enable_bitmapscan = off;
  
  EXPLAIN (COSTS OFF)
  SELECT names
    FROM tags
   WHERE names &^| ARRAY['gro', 'pos'];
  
  SELECT names
    FROM tags
   WHERE names &^| ARRAY['gro', 'pos'];
  
  DROP TABLE tags;
  