これはPGroonga 2.0.0以降用のドキュメントです。PGroonga 1.Xを使っているならPGroonga 1.Xのドキュメントを見てください。

How to do full-text-search on jsonb type column

jsonb type comes from PostgreSQL 9.4, this document will help you to try use PGroonga on jsonb type.

Create table schema and index

Here is the sample to create a table with jsonb type:

CREATE TABLE jsonb_table (
  id serial,
  data jsonb,
  PRIMARY KEY (id)
);

Then create index on jsonb:

Note that pgroonga_jsonb_ops_v2 only supports less than 4KiB string data in a jsonb column; if not certain about the length of jsonb data pgroonga_jsonb_full_text_search_ops_v2 should be used as index method.

CREATE INDEX pgroonga_index_jsonb_table_data ON jsonb_table
   USING pgroonga ("data" pgroonga_jsonb_full_text_search_ops_v2);

Let us add some data for test:

INSERT INTO jsonb_table (data)
  VALUES ('{"category":"server"}');
INSERT INTO jsonb_table (data)
  VALUES ('{"category":"user"}');
INSERT INTO jsonb_table (data)
  VALUES ('{"category":"server"}');
INSERT INTO jsonb_table (data)
  VALUES ('{"category":"user", "message": "user is logged in"}');

Now you can use full text search by PGroonga on data column like below:

SELECT id
  FROM jsonb_table
 WHERE data &@ 'user';
--  id
-- ----
--   2
--   4
-- (2 rows)

Score function on jsonb column

With pgroonga_score(tableoid, ctid) can get score of full jsonb column:

SELECT id,
       pgroonga_score(tableoid, ctid) AS score
  FROM jsonb_table
 WHERE data &@ 'user';
--  id | score
-- ----+-------
--   2 |     1
--   4 |     2
-- (2 rows)

If you want to score on specified JSON field, you must create index on that field:

CREATE INDEX pgroonga_index_jsonb_title ON jsonb_table
 USING pgroonga ((data->>'category'));

Note that jsonb->>'field' is text type and jsonb->'field' is jsonb type.

With this index, you can get score on jsonb field:

SELECT id,
       pgroonga_score(tableoid, ctid) AS score
  FROM jsonb_table
 WHERE data->>'category' &@ 'user';
--  id | score
-- ----+-------
--   2 |     1
--   4 |     1
-- (2 rows)