Creating a Session for Snowpark Scala¶
To use Snowpark in your application, you need to create a session. For convenience in writing code, you can also import the names of packages and objects.
Importing Names from Packages and Objects for Snowpark¶
The Snowpark API provides a number of classes, objects, and functions that are available in different packages. For convenience, you can import the class, object, and function names from packages and objects to avoid having to use qualified names.
The com.snowflake.snowpark package contains the main classes for the Snowpark API. To import the names in this package, use:
The com.snowflake.snowpark.functions object defines utility functions (including system-defined functions). To import the function names from this object, use:
The com.snowflake.snowpark.types package defines classes and objects that you can use to define schemas for semi-structured data.
If you used the
run.sh script to start the Scala REPL, the script already imports names
Creating a Session for Snowpark¶
The first step in using the library is establishing a session with the Snowflake database. To create a session, use the
SessionBuilder object. You can access the
SessionBuilder object through the
builder field in the
Session companion object:
import com.snowflake.snowpark._ ... // Get a SessionBuilder object. val builder = Session.builder
To provide the details to establish a session with a Snowflake database (for example, the account identifier, user name, etc.),
either create a properties file (a text file) or programmatically build a
Map containing the properties.
In the properties file or
Map, set the following properties:
URL: Set this to the URL for your account in the form
See Account Identifiers.
If the account identifier contains underscores (
_), replace those underscores with hyphens (
Any additional JDBC parameters (see JDBC Driver Connection Parameter Reference in the JDBC driver documentation) needed to connect to Snowflake (e.g.
To change the logging level (e.g. from
DEBUG), see Changing the Logging Settings.
snowpark_request_timeout_in_seconds: Set this to the maximum number of seconds that the Snowpark library should wait in the following cases:
Waiting for dependencies to be uploaded to a stage.
Waiting for an asynchronous action to complete.
The default value of this property is 86400 seconds (1 day).
This property was introduced in Snowpark 0.10.0.
To authenticate, you can use the same mechanisms that the JDBC Driver supports. For example, you can use:
password-based authentication (by setting the
For key-pair authentication, you can either:
PRIVATE_KEY_FILEproperty to the path to the private key file.
If the private key is encrypted, set the
PRIVATE_KEY_FILE_PWDproperty to the passphrase for decrypting the key.
PRIVATEKEYproperty to the string value of the unencrypted private key from the private key file. (If the private key is encrypted, you must decrypt the key before setting it as the value of the
To create the session:
Set the properties in the
If you created a properties file, pass the path to the properties file to the
If you programmatically built a
Mapof the properties, pass the
Both methods return a
builderobject that has these properties.
createmethod of the
builderobject to establish the session.
The following is an example of a properties file that sets the basic parameters for connecting to a Snowflake database. The
example is set up to use key-pair authentication. Set
PRIVATE_KEY_FILE to the path to the private key file. In addition,
if the private key is encrypted, you must set
PRIVATE_KEY_FILE_PWD to the passphrase for decrypting the private key:
# profile.properties file (a text file) URL = https://<account_identifier>.snowflakecomputing.com USER = <username> PRIVATE_KEY_FILE = </path/to/private_key_file.p8> PRIVATE_KEY_FILE_PWD = <if the private key is encrypted, set this to the passphrase for decrypting the key> ROLE = <role_name> WAREHOUSE = <warehouse_name> DB = <database_name> SCHEMA = <schema_name>
As an alternative, you can set the
PRIVATEKEY property to the unencrypted private key from the private key file.
# profile.properties file (a text file) URL = https://<account_identifier>.snowflakecomputing.com USER = <username> PRIVATEKEY = <unencrypted_private_key_from_the_private_key_file> ROLE = <role_name> WAREHOUSE = <warehouse_name> DB = <database_name> SCHEMA = <schema_name>
The following example uses this properties file to create a new session:
// Create a new session, using the connection properties // specified in a file. val session = Session.builder.configFile("/path/to/properties/file").create
The following example uses a Map to set the properties:
// Create a new session, using the connection properties // specified in a Map. val session = Session.builder.configs(Map( "URL" -> "https://<account_identifier>.snowflakecomputing.com", "USER" -> "<username>", "PRIVATE_KEY_FILE" -> "</path/to/private_key_file.p8>", "PRIVATE_KEY_FILE_PWD" -> "<if the private key is encrypted, set this to the passphrase for decrypting the key>", "ROLE" -> "<role_name>", "WAREHOUSE" -> "<warehouse_name>", "DB" -> "<database_name>", "SCHEMA" -> "<schema_name>" )).create
Closing a Session¶
If you no longer need to use a session for executing queries and you want to cancel any queries that are currently running, call
close method of the
Session object. For example:
// Close the session, cancelling any queries that are currently running, and // preventing the use of this Session object for performing any subsequent queries. session.close();