REFRESH

Stored query results in are not automatically updated to reflect the latest state of the table(s) they query. The REFRESH updates the stored query results of a materialized view.

CockroachDB does not support materialized views that are refreshed on .

Required privileges

The user must be the of the materialized view or have privileges.

Synopsis

Parameters

Parameter	Description
opt\_concurrently	CONCURRENTLY (Default behavior) This keyword has no effect. It is present for PostgreSQL compatibility. All materialized views are refreshed concurrently with other jobs.
view\_name	The name of the materialized view to refresh.
opt\_clear\_data	WITH DATA (Default behavior) Refresh the stored query results. WITH NO DATA Drop the query results of the materialized view from storage.

Example

The following example uses the , populated with some workload values.

Suppose that you create a materialized view on the bank table:

> CREATE MATERIALIZED VIEW overdrawn_accounts
  AS SELECT id, balance
  FROM bank
  WHERE balance < 0;

> SELECT * FROM overdrawn_accounts;

  id  | balance
------+----------
    1 |  -17643
    3 |   -5928
   13 |   -3700
...
(402 rows)

Now suppose that you update the balance values of the bank table:

> UPDATE bank SET balance = 0 WHERE balance < 0;

UPDATE 402

The changes can be seen in the table with a simple SELECT statement against the table:

> SELECT id, balance
FROM bank
WHERE balance < 0;

  id | balance
-----+----------
(0 rows)

Recall that materialized views do not automatically update their stored results. Selecting from overdrawn_accounts returns stored results, which are outdated:

> SELECT * FROM overdrawn_accounts;

  id  | balance
------+----------
    1 |  -17643
    3 |   -5928
   13 |   -3700
...
(402 rows)

To update the materialized view’s results, use a statement:

> REFRESH MATERIALIZED VIEW overdrawn_accounts;

> SELECT * FROM overdrawn_accounts;

  id | balance
-----+----------
(0 rows)

See also