text: CREATE TABLE memos (
    title text,
    contents text[]
  );
  
  INSERT INTO memos
       VALUES ('PostgreSQL',
               ARRAY['PostgreSQL is an OSS RDBMS',
                     'PostgreSQL has partial full-text search support']);
  INSERT INTO memos
       VALUES ('Groonga', ARRAY['Groonga is an OSS full-text search engine',
                                'Groonga has full full-text search support']);
  INSERT INTO memos
      VALUES ('PGroonga',
              ARRAY['PGroonga is an OSS PostgreSQL extension',
                    'PGroonga adds full full-text search support based on Groonga to PostgreSQL']);
  
  CREATE INDEX pgroonga_memos_index ON memos
    USING pgroonga (contents pgroonga.text_array_full_text_search_ops_v2);
  
  SET enable_seqscan = off;
  SET enable_indexscan = on;
  SET enable_bitmapscan = off;
  
  EXPLAIN (COSTS OFF)
  SELECT title, contents
    FROM memos
   WHERE contents &@| Array['rdbms', 'engine'];
  
  SELECT title, contents
    FROM memos
   WHERE contents &@| Array['rdbms', 'engine'];
  
  DROP TABLE memos;
  