text: CREATE TABLE memos (
    title text,
    tags varchar(1023)[]
  );
  
  INSERT INTO memos VALUES ('PostgreSQL', ARRAY['PostgreSQL']);
  INSERT INTO memos VALUES ('Groonga', ARRAY['Groonga']);
  INSERT INTO memos VALUES ('PGroonga', ARRAY['PostgreSQL', 'Groonga']);
  
  CREATE INDEX pgroonga_memos_index ON memos
    USING pgroonga (tags pgroonga_varchar_array_term_search_ops_v2);
  
  SET enable_seqscan = off;
  SET enable_indexscan = off;
  SET enable_bitmapscan = on;
  
  EXPLAIN (COSTS OFF)
  SELECT title, tags
    FROM memos
   WHERE tags %% 'Groonga';
  
  SELECT title, tags
    FROM memos
   WHERE tags %% 'Groonga';
  
  DROP TABLE memos;
  