text: CREATE TABLE fruits (
    id int,
    items jsonb
  );
  INSERT INTO fruits VALUES (1, '["apple"]');
  INSERT INTO fruits VALUES (2, '["banana", "apple"]');
  INSERT INTO fruits VALUES (3, '["peach"]');
  CREATE INDEX pgroonga_index ON fruits
    USING pgroonga (items pgroonga_jsonb_ops);
  DELETE FROM fruits WHERE id = 1;
  VACUUM;
  SET enable_seqscan = off;
  SET enable_indexscan = on;
  SET enable_bitmapscan = off;
  SELECT id, items
    FROM fruits
   WHERE items &` 'string == "apple"'
   ORDER BY id;
   id |        items        
  ----+---------------------
    2 | ["banana", "apple"]
  (1 row)
  
  DROP TABLE fruits;
  