text: CREATE TABLE memos (
    id integer,
    content text
  );
  
  INSERT INTO memos VALUES (1, 'PostgreSQL is a RDBMS.');
  INSERT INTO memos VALUES (2, 'Groonga is fast full text search engine.');
  INSERT INTO memos VALUES (3, 'PGroonga is a PostgreSQL extension that uses Groonga.');
  INSERT INTO memos VALUES (4, 'groonga command is provided.');
  
  CREATE INDEX grnindex ON memos USING pgroonga (content pgroonga_text_regexp_ops);
  
  SET enable_seqscan = off;
  SET enable_indexscan = off;
  SET enable_bitmapscan = on;
  
  SELECT id, content
    FROM memos
   WHERE content LIKE '%Groonga%';
  
  DROP TABLE memos;
  