REFRESH MATERIALIZED VIEW — replace the contents of a materialized view
REFRESH MATERIALIZED VIEW [ CONCURRENTLY ] name
[ WITH [ NO ] DATA ]
REFRESH MATERIALIZED VIEW
completely replaces the
contents of a materialized view. To execute this command you must be the
owner of the materialized view. The old contents are discarded. If
WITH DATA
is specified (or defaults) the backing query
is executed to provide the new data, and the materialized view is left in a
scannable state. If WITH NO DATA
is specified no new
data is generated and the materialized view is left in an unscannable
state.
CONCURRENTLY
and WITH NO DATA
may not
be specified together.
CONCURRENTLY
Refresh the materialized view without locking out concurrent selects on the materialized view. Without this option a refresh which affects a lot of rows will tend to use fewer resources and complete more quickly, but could block other connections which are trying to read from the materialized view. This option may be faster in cases where a small number of rows are affected.
This option is only allowed if there is at least one
UNIQUE
index on the materialized view which uses only
column names and includes all rows; that is, it must not be an
expression index or include a WHERE
clause.
This option may not be used when the materialized view is not already populated.
Even with this option only one REFRESH
at a time may
run against any one materialized view.
name
The name (optionally schema-qualified) of the materialized view to refresh.
While the default index for future
CLUSTER
operations is retained, REFRESH MATERIALIZED VIEW
does not
order the generated rows based on this property. If you want the data
to be ordered upon generation, you must use an ORDER BY
clause in the backing query.
This command will replace the contents of the materialized view called
order_summary
using the query from the materialized
view's definition, and leave it in a scannable state:
REFRESH MATERIALIZED VIEW order_summary;
This command will free storage associated with the materialized view
annual_statistics_basis
and leave it in an unscannable
state:
REFRESH MATERIALIZED VIEW annual_statistics_basis WITH NO DATA;
REFRESH MATERIALIZED VIEW
is a
LightDB extension.