Presto 326 Documentation

6.16. MemSQL Connector

6.16. MemSQL Connector

The MemSQL connector allows querying and creating tables in an external MemSQL database. The MemSQL connector is very similar to the MySQL connector with the only difference being the underlying driver.

Configuration

To configure the MemSQL connector, create a catalog properties file in etc/catalog named, for example, memsql.properties, to mount the MemSQL connector as the memsql catalog. Create the file with the following contents, replacing the connection properties as appropriate for your setup:

connector.name=memsql
connection-url=jdbc:mariadb://example.net:3306
connection-user=root
connection-password=secret

Multiple MemSQL Servers

You can have as many catalogs as you need, so if you have additional MemSQL servers, simply add another properties file to etc/catalog with a different name (making sure it ends in .properties). For example, if you name the property file sales.properties, Presto will create a catalog named sales using the configured connector.

Querying MemSQL

The MemSQL connector provides a schema for every MemSQL database. You can see the available MemSQL databases by running SHOW SCHEMAS:

SHOW SCHEMAS FROM memsql;

If you have a MemSQL database named web, you can view the tables in this database by running SHOW TABLES:

SHOW TABLES FROM memsql.web;

You can see a list of the columns in the clicks table in the web database using either of the following:

DESCRIBE memsql.web.clicks;
SHOW COLUMNS FROM memsql.web.clicks;

Finally, you can access the clicks table in the web database:

SELECT * FROM memsql.web.clicks;

If you used a different name for your catalog properties file, use that catalog name instead of memsql in the above examples.

MemSQL Connector Limitations

The following SQL statements are not yet supported: