text: CREATE TABLE memos (
    id integer,
    content text
  );
  
  INSERT INTO memos VALUES (1, 'りんご');
  INSERT INTO memos VALUES (2, 'リンゴ');
  INSERT INTO memos VALUES (3, '林檎');
  
  CREATE INDEX pgrn_index ON memos
   USING pgroonga (content)
    WITH (token_filters = 'TokenFilterNFKC100("unify_kana", true)');
  
  SET enable_seqscan = off;
  SET enable_indexscan = on;
  SET enable_bitmapscan = off;
  
  EXPLAIN (COSTS OFF)
  SELECT id, content
    FROM memos
   WHERE content &@ 'りんご';
  
  SELECT id, content
    FROM memos
   WHERE content &@ 'りんご';
  
  DROP TABLE memos;
  