CREATE DATABASE

The CREATE DATABASE statement creates a new, empty database. A single SereneDB server can host many independent databases (the default is postgres); switch between them with USE or by connecting to one directly.

Examples

Create a database named app_production:

SQL

DROP DATABASE IF EXISTS app_production;
CREATE DATABASE app_production;

Use IF NOT EXISTS so the statement succeeds even when the database already exists, instead of raising an error:

SQL

CREATE DATABASE IF NOT EXISTS app_production;

Once created, you can connect to it like any other database — for example with psql:

sh

psql -h localhost -p 7890 -d app_production

As an alternative to reconnecting, switch to the new database within the current session with the USE statement:

SQL

USE app_production;

Storage options

WITH sets how the new database stores its tables:

SQL

DROP DATABASE IF EXISTS app_archive;
CREATE DATABASE app_archive WITH (BLOCK_SIZE = 16384, ROW_GROUP_SIZE = 1048576);
SELECT block_size FROM pragma_database_size() WHERE database_name = 'app_archive';

 block_size
------------
      16384

Option	Description	Default
BLOCK_SIZE	The block size of the database file in bytes: a power of two from 16384 to 262144.	262144
ROW_GROUP_SIZE	The number of rows in a row group: a multiple of 2048.	122880

The options are stored with the database, so the server opens it with them again after a restart. BLOCK_SIZE is fixed once the file exists; ROW_GROUP_SIZE applies to the row groups written from then on. Any other option is refused.

See also

• ATTACH / DETACH — attach an existing database file
• USE — switch the active database

Syntax

Syntax