StarRocks connector#

The StarRocks connector allows querying and creating tables in an external StarRocks instance, enabling you to join StarRocks data with any other connector that Trino supports.

Requirements#

To connect to StarRocks, you need:

StarRocks 3.1 or higher.
Network access from the Trino coordinator and workers to StarRocks FE&BE service. Port 9030 is the metadata default port. Port 8030 is the HTTP query plan default port.

Configuration#

To configure the StarRocks connector, create a catalog properties file in etc/catalog named, for example, example.properties, to mount the StarRocks catalog. Note: The catalog name will display example derived from the property file name.

Here is a standard StarRocks connector properties file.

connector.name=starrocks
jdbc-url=jdbc:mysql://fe:9030
scan-url=be:8030
username=root
password=your_password

StarRocks implements the Flink client pulling protocol. The StarRocks connector uses the MySQL JDBC driver to interact with StarRocks to fetch metadata. Using metadata to generate query plan and sending to BE instance to pulling data. The jdbc-url defines the connection information and parameters to pass to the MySQL JDBC driver. The supported parameters for the URL are available in the MySQL Developer Guide. Some parameters can have adverse effects on the connector behavior or not work with the connector.

The username and password are typically required and determine the user credentials for the connection, often a service user. You can use :doc:secrets </security/secrets> to avoid actual values in the catalog properties files.

StarRocks connector properties#
Property	Description	Default
`starrocks.dynamic_filtering_wait_timeout`	The timeout for waiting for dynamic filtering to finish.	`10s`

Multiple StarRocks servers#

To connect to multiple StarRocks servers, add another properties file to etc/catalog with a different name, for example, starrocks.properties to add the catalog starrocks for the second StarRocks instance.

Multiple StarRocks instance#

To connect to multiple StarRocks instance, you can add different address in scan-url properties.

connector.name=starrocks
jdbc-url=jdbc:mysql://fe:9030
scan-url=fe:8030,fe2:8030,fe3:8030
username=root
password=your_password

Type mapping#

StarRocks supports these data types https://docs.starrocks.io/en-us/latest/sql-reference/sql-statements/data-types_.

StarRocks SQL data type name	Map to Trino type	notes
`BOOLEAN`	`TINYINT`	Possible values: `0` and `1`
`TINYINT`	`TINYINT`	Possible values: `-128`, `127`, etc.
`SMALLINT`	`SMALLINT`	Possible values: `-32768`, `32767`, etc.
`INT`	`INTEGER`	Possible values: `-2147483648`, `2147483647`, etc.
`BIGINT`	`BIGINT`	Possible values: `-9223372036854775808`, `9223372036854775807`, etc.
`DECIMAL(p,s)`	`DECIMAL(p,s)`	The range of p is [1,38], and the range of S is [0, p]. The default value of s is 0.
`DOUBLE`	`DOUBLE`	Possible values: `3.14`, `-10.24`, etc.
`FLOAT`	`REAL`	Possible values: `3.14`, `-10.24`, etc.
`CHAR(n)`	`CHAR(n)`	Length n must between 1 and 255, unit is bytes Possible values: `hello`, `Trino`, etc.
`VARCHAR(n)`	`VARCHAR(n)`	Length n must between 1 and 1048576, unit is bytes. Possible values: `hello`, `Trino`, etc.
`DATE`	`DATE`	`1972-01-01`, `2021-07-15`, etc.
`DATETIME`	`TIMESTAMP`	Possible values: `2021-07-15 12:00:00`, `2021-07-15 12:00:00.123`, etc.
`LARGEINT`	`DECIMAL`	Possible values: `-2^(127)-1`, `2^(127)-1`, etc.

No other types are supported.

Querying StarRocks#

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

SHOW SCHEMAS FROM example;

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

SHOW TABLES FROM example.web;

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

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

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

SELECT * FROM example.web.clicks;

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

SQL support#

The connector ONLY provides read access to data and metadata in the StarRocks database. In addition to the :ref:globally available <sql-globally-available> and :ref:read operation <sql-read-operations> statements, the connector supports the following statements:

Performance#

The connector includes a number of performance improvements, detailed in the following sections.