CREATE DATABASE

Creates a database.

Syntax

CREATE DATABASE [IF NOT EXISTS] <database_name> [<sync_options>] [PARTITIONS n]
[<create_specification>]
[SUB_PARTITIONS n]
[{FOR | INTO | ON} <object_store_settings>]
<sync_options>:
WITH {SYNC | ASYNC} DURABILITY
| WITH {SYNC | ASYNC} REPLICATION
| WITH SYNC DURABILITY SYNC REPLICATION | WITH ASYNC DURABILITY ASYNC REPLICATION
<create_specification>:
[DEFAULT] CHARACTER SET [=] charset_name
<object_store_settings>:
<S3_object_store_configuration>
| <AZURE_object_store_configuration>
| <GCS_object_store_configuration>
<S3_object_store_configuration>:
S3 { '<bucket-name>' | '<bucket-name/path>' }
[CONFIG '<configuration_json>',<'{"verify_ssl":false|true}'>]
CREDENTIALS '<credentials_json>'
<AZURE_object_store_configuration>:
AZURE { '<container-name>' | '<container-name/object-name>' | '<container-name/prefix/object-name>' }
[CONFIG '<configuration_json>']
CREDENTIALS '<credentials_json>'
<GCS_object_store_configuration>:
GCS {'<bucket-name>' | '<bucket-name/path>' }
[CONFIG '<configuration_json>']
CREDENTIALS '<credentials_json>'
-- "schema" is an alias for "database"
CREATE SCHEMA [IF NOT EXISTS]..

Note

In the SingleStore Free version, this command does not support unlimited storage databases. For more information, see SingleStore Editions.

Remarks

  • database_name is the name to assign to this new SingleStore database. Do not use the _XX suffix (such as test_database_01) while naming a SingleStore database as it may cause a mismatch with the database partition ordinals (sharded databases on each leaf node).

  • Database names are case-sensitive. Databases named DB and db are not the same objects and will be treated as such when granting permissions to users.

  • CONFIG and CREDENTIALS can be specified in either order (CONFIG followed by CREDENTIALS or CREDENTIALS followed by CONFIG). For configuration examples refer BACKUP DATABASE

  • CONFIG '{"verify_ssl":false|true}' allows you to connect to an unverified SSL certificate in S3 when using the option verify_ssl:false

  • To create a local storage database, exclude the {FOR | INTO | ON} <object_store_settings> option. To create an unlimited storage database use the {FOR | INTO | ON} <object_store_settings> option. Note that FOR, INTO, and ON are synonyms and their functionality is identical.

    Prior to creating an unlimited storage database, the enable_bottomless engine variable must be set to ON (the default value). For more information on local storage and unlimited storage databases, see Local and Unlimited Database Storage Concepts.

    Unlimited storage databases cannot be created in the SingleStore Free Edition.

  • WITH {SYNC | ASYNC} REPLICATION specifies whether high availability, redundancy-2 replication will be done synchronously or asynchronously. Synchronous replication from the master partitions will complete on all replicas before the commit of the transaction is acknowledged to the client application. If WITH {SYNC | ASYNC} REPLICATION is not specified, synchronous replication is used.

    See Replication and Durability Concepts for more information.

  • WITH {SYNC | ASYNC} DURABILITY specifies whether in-memory database updates you make using DDL and DML commands are also saved to the log on disk synchronously or asynchronously. Synchronous updates to the log on disk will complete before the commit of the transaction is acknowledged to the client application. If WITH {SYNC | ASYNC} DURABILITY is not specified, async durability is used.

    Note

    SYNC DURABILITY cannot be disabled once a database is created.

    See Replication and Durability Concepts for more information.

  • This command causes implicit commits. Refer to COMMIT for more information.

  • You cannot specify WITH SYNC DURABILITY ASYNC REPLICATION.

  • PARTITIONS n allows you to set the total number of partitions that the data will be split into. By default this is controlled by the default_partitions_per_leaf variable. Note that n refers to the total number of partitions across all leaves. Refer to the Flexible Parallelism page for more information.

  • SUB_PARTITIONS n allows you to set the number of sub-partitions for a database per physical partition at the time of database creation. Using this optional clause in the CREATE DATABASE command will override the value set by the sub_to_physical_partition_ratio variable. The value of n must be set at 0 or a power of 2 value of the physical partition count. For example, if the number of partitions is 6, the number of sub-partitions must be 6 * (a power of 2 value). Refer to the Flexible Parallelism page for more information.

  • The CREATE DATABASE ... DEFAULT CHARSET= syntax is accepted by SingleStore for compatibility with MySQL, but it has no effect. The database and its schema objects use the server character set and collation. Character set and collation defaults can be set during table creation. See CREATE TABLE for more information.

  • Node Requirements for SingleStore Commands

  • The ceph_mode flag has been deprecated.

  • Refer to the Permission Matrix for the required permission.

Examples

CREATE DATABASE with Default Options

The following example creates a local database that uses all of the default options.

CREATE DATABASE IF NOT EXISTS test;

CREATE DATABASE Using Sync Durability and Sync Replication

The following example creates a local database that uses sync durability and sync replication. The latter is enabled by default.

CREATE DATABASE IF NOT EXISTS test WITH SYNC DURABILITY;

CREATE DATABASE Unlimited Storage

The following example creates an unlimited storage database.

CREATE DATABASE bottomless_db ON S3 "bottomless_db_bucket/bottomless_db_folder"
CONFIG '{"region":"us-east-1", "verify_ssl":false}'
CREDENTIALS '{"aws_access_key_id":"your_access_key_id","aws_secret_access_key":"your_secret_access_key"}';

CREATE DATABASE SUB_PARTITIONS

The following command returns the default number of sub-partitions:

SELECT @@sub_to_physical_partition_ratio;
+-----------------------------------+
| @@sub_to_physical_partition_ratio |
+-----------------------------------+
| 4 |
+-----------------------------------+

The following example uses the SUB_PARTITONS n clause to create a database with 96 sub-partitions.

CREATE DATABASE test1 PARTITIONS 6 SUB_PARTITIONS 96;
SELECT DATABASE_NAME, NUM_PARTITIONS, NUM_SUB_PARTITIONS
FROM information_schema.distributed_databases
WHERE DATABASE_NAME = 'test1';
+---------------+----------------+--------------------+
| DATABASE_NAME | NUM_PARTITIONS | NUM_SUB_PARTITIONS |
+---------------+----------------+--------------------+
| test1         |              6 |                 96 |
+---------------+----------------+--------------------+

Assuming the default number of physical partitions is 8, the following example uses the SUB_PARTITONS n clause to create a database with 64 sub-partitions If n is not power of 2 not

CREATE DATABASE test2 SUB_PARTITIONS 64;
SELECT DATABASE_NAME, NUM_PARTITIONS, NUM_SUB_PARTITIONS
FROM information_schema.distributed_databases
WHERE DATABASE_NAME = 'test2';
+---------------+----------------+--------------------+
| DATABASE_NAME | NUM_PARTITIONS | NUM_SUB_PARTITIONS |
+---------------+----------------+--------------------+
| test2         |              8 |                 64 |
+---------------+----------------+--------------------+

If n in the SUB_PARTITIONS n clause is not a power of 2, an error is generated and the database will not be created.

CREATE DATABASE test3 PARTITIONS 6 SUB_PARTITIONS 36;
ERROR 1504 (HY000): Value of sub_partitions (36) needs to be a power-of-2 multiple of the partition count (6)
CREATE DATABASE test4 SUB_PARTITIONS 40;
ERROR 1504 (HY000): Value of sub_partitions (40) needs to be a power-of-2 multiple of the partition count (8)

Last modified: May 31, 2024

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