text: CREATE TABLE memos (
    id integer,
    record jsonb
  );
  
  INSERT INTO memos VALUES
    (1, '{"title": "PostgreSQL", "content": "PostgreSQL is a RDBMS."}');
  INSERT INTO memos VALUES
    (2, '{"title": "Groonga", "content": "Groonga is fast full text search engine."}');
  INSERT INTO memos VALUES
    (3, '{"title": "PGroonga", "content": "PGroonga is a PostgreSQL extension that uses Groonga."}');
  
  CREATE INDEX grnindex ON memos
   USING pgroonga (record pgroonga_jsonb_full_text_search_ops_v2);
  
  SET enable_seqscan = off;
  SET enable_indexscan = off;
  SET enable_bitmapscan = on;
  
  EXPLAIN (COSTS OFF)
  SELECT id, record
    FROM memos
   WHERE record &@ 'groonga';
  
  SELECT id, record
    FROM memos
   WHERE record &@ 'groonga';
  
  DROP TABLE memos;
  