SHOW CLUSTERS
mz_introspection
cluster. To switch clusters, use SET CLUSTER = mz_introspection;
.
SHOW CLUSTERS
lists the clusters configured in Materialize.
Syntax
Pre-installed clusters
When you enable a Materialize region, several clusters that are used to improve the user experience, as well as support system administration tasks, will be pre-installed.
default
cluster
A cluster named default
with a single xsmall
replica
named r1
will be pre-installed in every environment. You can modify or drop
this cluster or its replicas at any time.
cluster
session parameter is default
.
If the default
cluster is dropped, you must run SET cluster
to choose a valid cluster in order to run SELECT
queries.
mz_introspection
system cluster
A system cluster named mz_introspection
will be pre-installed in every
environment. This cluster has several indexes installed to speed up common
introspection queries, like SHOW
commands and queries using the system
catalog. It is recommended to switch to the mz_introspection
cluster for
improved performance when executing these statements.
The following characteristics apply to the mz_introspection
cluster:
- You are not billed for this cluster.
- You cannot create indexes or materialized views on this cluster.
- You cannot drop this cluster.
- You can run
SELECT
orSUBSCRIBE
statements on this cluster.
mz_system
system cluster
A system cluster named mz_system
will be pre-installed in every environment.
This cluster is used for various internal system monitoring tasks.
The following characteristics apply to the mz_system
cluster:
- You are not billed for this cluster.
- You cannot create indexes or materialized views on this cluster.
- You cannot drop this cluster.
- You cannot run
SELECT
orSUBSCRIBE
on this cluster.
Examples
SET CLUSTER = mz_introspection;
SHOW CLUSTERS;
name
---------------------
default
auction_house
mz_introspection
mz_system
SHOW CLUSTERS LIKE 'auction_%';
name
---------------------
auction_house