Before build and install **rum** you should ensure following:

* PostgreSQL version is 9.6.

Typical installation procedure may look like this:

$ git clone https://github.com/postgrespro/rum

$ cd rum

$ make USE_PGXS=1

$ sudo make USE_PGXS=1 install

$ make USE_PGXS=1 installcheck

$ psql DB -c "CREATE EXTENSION rum;"

The **rum** module provides the access method **rum** and the operator class

**rum_tsvector_ops**.

The module provides new operators.

| Operator | Returns | Description

| ------------------- | ------- | ----------------------------------------------

| tsvector >< tsquery | float4 | Returns distance between tsvector and tsquery.

Let us assume we have the table:

CREATE TABLE test_rum(t text, a tsvector);

CREATE TRIGGER tsvectorupdate

BEFORE UPDATE OR INSERT ON test_rum

FOR EACH ROW EXECUTE PROCEDURE tsvector_update_trigger('a', 'pg_catalog.english', 't');

INSERT INTO test_rum(t) VALUES ('The situation is most beautiful');

INSERT INTO test_rum(t) VALUES ('It is a beautiful');

INSERT INTO test_rum(t) VALUES ('It looks like a beautiful place');

To create the **rum** index we need create an extension:

CREATE EXTENSION rum;

Then we can create new index:

CREATE INDEX rumidx ON test_rum USING rum (a rum_tsvector_ops);

And we can execute the following queries:

t | rank

The situation is most beautiful | 0.0303964

It is a beautiful | 0.0303964

It looks like a beautiful place | 0.0607927

(3 rows)

t | rank

The situation is most beautiful | 0.0303964

It looks like a beautiful place | 0.0303964

(2 rows)