The CREATE DATABASE
statement creates a new CockroachDB database.
The CREATE DATABASE
statement performs a schema change. For more information about how online schema changes work in CockroachDB, see Online Schema Changes.
Required privileges
To create a database, the user must be a member of the admin
role or must have the CREATEDB
parameter set.
Synopsis
Parameters
Parameter | Description |
---|---|
IF NOT EXISTS |
Create a new database only if a database of the same name does not already exist; if one does exist, do not return an error. |
name |
The name of the database to create, which must be unique and follow these identifier rules. Cockroach Labs recommends against starting your database name with the string cluster: . If your database name begins with this string, you must append the following to the URI connection string to connect to the cluster: &options=-ccluster=system |
encoding |
The CREATE DATABASE statement accepts an optional ENCODING clause for compatibility with PostgreSQL, but UTF-8 is the only supported encoding. The aliases UTF8 and UNICODE are also accepted. Values should be enclosed in single quotes and are case-insensitive.Example: CREATE DATABASE bank ENCODING = 'UTF-8' . |
CONNECTION LIMIT |
Supported for compatibility with PostgreSQL. A value of -1 indicates no connection limit. Values other than -1 are currently not supported. By default, CONNECTION LIMIT = -1 . (*) |
PRIMARY REGION region_name |
Create a multi-region database with region_name as the primary region.Allowed values include any region returned by SHOW REGIONS FROM CLUSTER . |
REGIONS region_name_list |
Create a multi-region database with region_name_list as database regions.Allowed values include any region returned by SHOW REGIONS FROM CLUSTER .To set database regions at database creation, a primary region must be specified in the same CREATE DATABASE statement. |
SURVIVE ZONE FAILURE (Default)SURVIVE REGION FAILURE |
Create a multi-region database with regional failure or zone failure survival goals. To set the regional failure survival goal, the database must have at least 3 database regions. Surviving zone failures is the default setting for multi-region databases. |
*
To control the maximum number of non-superuser (root
user or other admin
role) connections a gateway node can have open at one time, use the server.max_connections_per_gateway
cluster setting. If a new non-superuser connection would exceed this limit, the error message "sorry, too many clients already"
is returned, along with error code 53300
.
This setting may be useful until the CONNECTION LIMIT
syntax is fully supported.
Example
Create a database
CREATE DATABASE bank;
CREATE DATABASE
SHOW DATABASES;
database_name | owner | primary_region | regions | survival_goal
----------------+-------+----------------+---------+----------------
bank | demo | NULL | {} | NULL
defaultdb | root | NULL | {} | NULL
postgres | root | NULL | {} | NULL
system | node | NULL | {} | NULL
(4 rows)
Create fails (name already in use)
CREATE DATABASE bank;
ERROR: database "bank" already exists
SQLSTATE: 42P04
CREATE DATABASE IF NOT EXISTS bank;
CREATE DATABASE
SQL does not generate an error, but instead responds CREATE DATABASE
even though a new database wasn't created.
SHOW DATABASES;
database_name | owner | primary_region | regions | survival_goal
----------------+-------+----------------+---------+----------------
bank | demo | NULL | {} | NULL
defaultdb | root | NULL | {} | NULL
postgres | root | NULL | {} | NULL
system | node | NULL | {} | NULL
(4 rows)
Create a multi-region database
Suppose you start a cluster with region and zone localities specified at startup.
For this example, let's use a demo cluster, with the --demo-locality
flag to simulate a multi-region cluster:
cockroach demo --nodes=6 --demo-locality=region=us-east1,zone=us-east1-a:region=us-east1,zone=us-east1-b:region=us-central1,zone=us-central1-a:region=us-central1,zone=us-central1-b:region=us-west1,zone=us-west1-a:region=us-west1,zone=us-west1-b --no-example-database
SHOW REGIONS;
region | zones | database_names | primary_region_of
--------------+-------------------------------+----------------+--------------------
us-central1 | {us-central1-a,us-central1-b} | {} | {}
us-east1 | {us-east1-a,us-east1-b} | {} | {}
us-west1 | {us-west1-a,us-west1-b} | {} | {}
(3 rows)
If regions are set at cluster start-up, you can create multi-region databases in the cluster that use the cluster regions.
Use the following command to specify regions and survival goals at database creation:
CREATE DATABASE bank PRIMARY REGION "us-east1" REGIONS "us-east1", "us-central1", "us-west1" SURVIVE REGION FAILURE;
SHOW DATABASES;
database_name | owner | primary_region | regions | survival_goal
----------------+-------+----------------+---------------------------------+----------------
bank | demo | us-east1 | {us-central1,us-east1,us-west1} | region
defaultdb | root | NULL | {} | NULL
postgres | root | NULL | {} | NULL
system | node | NULL | {} | NULL
(4 rows)
SHOW REGIONS FROM DATABASE bank;
database | region | primary | zones
-----------+-------------+---------+--------------------------------
bank | us-east1 | true | {us-east1-a,us-east1-b}
bank | us-central1 | false | {us-central1-a,us-central1-b}
bank | us-west1 | false | {us-west1-a,us-west1-b}
(3 rows)
Create a multi-region database with a secondary region
You can add a secondary region to a multi-region database for failover purposes. If the primary region fails, the secondary region becomes the new primary region.
To add a secondary region during database creation, use the following steps:
Start a
cockroach demo
cluster as described in the example Create a multi-region database.Issue a
CREATE DATABASE
statement like the following. It is the same as in the Create a multi-region database example, except that it adds aSECONDARY REGION {region}
clause:
CREATE DATABASE bank PRIMARY REGION "us-east1" REGIONS "us-east1", "us-central1", "us-west1" SURVIVE REGION FAILURE SECONDARY REGION "us-west1";
CREATE DATABASE
For more information about secondary regions, see Secondary regions.
Secondary regions are not compatible with databases containing REGIONAL BY ROW
tables. CockroachDB does not prevent you from defining secondary regions on databases with regional by row tables, but the interaction of these features is not supported.
Therefore, Cockroach Labs recommends that you avoid defining secondary regions on databases that use regional by row table configurations.