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Snowflake

Snowflake is a cloud data warehouse.

Connect to Snowflake​

  1. In the Dremio console, click Add Data on the Home page.
  2. In the Add Data dialog, select Snowflake.
  3. Configure the connection using the sections below, then click Save.

General​

Perform these steps in the General tab:

  1. For Name, specify the name for the connection. The name cannot include the following special characters: /, :, [, or ].
  2. For Host, specify the Snowflake hostname in the format LOCATOR_ID.snowflakecomputing.com.
  3. For Port, enter the port number. The default port is 443.
note

The optional connection parameters are case-sensitive. For example, if the name of a warehouse uses uppercase only (e.g., WAREHOUSE1), specify it the same way in the Warehouse field.

  1. (Optional) For Database, specify the default database to use.
  2. (Optional) For Role, specify the default access-control role to use.
  3. (Optional) For Schema, specify the default schema to use.
  4. (Optional) For Warehouse, specify the warehouse that will provide resources for executing DML statements and queries.
  5. Under Authentication, you must choose one of the following authentication methods:
    • Login-password authentication:
      • For Username, enter your Snowflake username.
      • For Password, enter your Snowflake password.
    • Key-pair authentication (see Snowflake's key-pair documentation):
      • For Username, enter your Snowflake username.
      • For Private Key, enter your generated Snowflake private key in Privacy Enhanced Mail (PEM) format.
      • (Optional) For Private key passphrase, enter the passphrase if you are using an encrypted private key.

Advanced​

On the Advanced Options page, you can set values for these optional options:

OptionDescription
Maximum Idle ConnectionsThe total number of connections allowed to be idle at a given time. The default is 8.
Connection Idle TimeThe amount of time (in seconds) allowed for a connection to remain idle before the connection is terminated. The default is 60 seconds.
Query TimeoutThe amount of time (in seconds) allowed to wait for the results of a query. If this time expires, the connection being used is returned to an idle state.

Reflection Refresh​

On the Reflection Refresh page, set the policy that controls how often Reflections are scheduled to be refreshed automatically, as well as the time limit after which Reflections expire and are removed.

OptionDescription
Never refreshSelect to prevent automatic Reflection refresh, default is to automatically refresh.
Refresh everyHow often to refresh Reflections, specified in hours, days or weeks. This option is ignored if Never refresh is selected.
Never expireSelect to prevent Reflections from expiring, default is to automatically expire after the time limit below.
Expire afterThe time limit after which Reflections expire and are removed from Dremio, specified in hours, days or weeks. This option is ignored if Never expire is selected.

Metadata Options​

On the Metadata page, you can configure settings to refresh metadata and handle datasets.

Dataset Handling​

These are the optional Dataset Handling parameters.

ParameterDescription
Remove dataset definitions if underlying data is unavailableBy default, Dremio removes dataset definitions if underlying data is unavailable. Useful when files are temporarily deleted and added back in the same location with new sets of files.

Metadata Refresh​

These are the optional Metadata Refresh parameters:

  • Dataset Discovery: The refresh interval for fetching top-level object names such as databases and tables. Set the time interval using this parameter.

    ParameterDescription
    (Optional) Fetch everyYou can choose to set the frequency to fetch object names in minutes, hours, days, or weeks. The default frequency is 1 hour.

  • Dataset Details: The metadata that Dremio needs for query planning such as information required for fields, types, shards, statistics, and locality. These are the parameters to fetch the dataset information.

    ParameterDescription
    Fetch modeYou can choose to fetch only from queried datasets, which is set by default. Dremio updates details for previously queried objects. Fetching from all datasets is deprecated.
    Fetch everyYou can choose to set the frequency to fetch dataset details in minutes, hours, days, or weeks. The default frequency is 1 hour.
    Expire afterYou can choose to set the expiry time of dataset details in minutes, hours, days, or weeks. The default expiry time is 3 hours.

Privileges​

This connection inherits privileges from Project settings. To grant specific users or roles additional privileges in this connection:

  1. Enter the username or role name that you want to grant access to and click the Add to Privileges button. The added user or role is displayed in the USERS/ROLES table.
  2. For the users or roles in the USERS/ROLES table, toggle the checkmark for each privilege you want to grant on the Dremio source that is being created.
  3. Click Save after setting the configuration.

See Privileges for additional information about privileges.

Edit a Snowflake Connection​

  1. On the Open Catalog page, under Connections, right-click the connection and select Settings.
  2. Update the connection configuration as needed.
  3. Click Save.

Delete a Snowflake Connection​

  1. On the Open Catalog page, under Connections, right-click the connection and select Delete.
  2. Click Delete to confirm.

You can use Amazon Web Services (AWS) PrivateLink to connect Dremio to a Snowflake account hosted on AWS through Snowflake-managed private connectivity. Use these steps when Dremio has enabled private source connectivity for your organization.

This configuration uses Snowflake's AWS PrivateLink and Snowflake model. In this model, you authorize the Dremio AWS account through Snowflake Support, provide Snowflake PrivateLink configuration values to Dremio, and Dremio creates the interface virtual private cloud (VPC) endpoint in Dremio infrastructure.

note

Snowflake accounts hosted on Microsoft Azure or Google Cloud are not supported with this configuration. Network Load Balancers (NLBs), proxies, and generic VPC endpoint services are also not supported. For Snowsight, Streamlit, Snowflake internal stages, Snowflake-managed storage volumes, Snowpark Container Services, and Client Redirect, use separate Snowflake guidance.

Prerequisites​

Before you start, confirm that the Snowflake account and the Dremio organization are ready for private connectivity.

Confirm all of the following:

  • Your Dremio organization has private source connectivity enabled.
  • Your Snowflake account is hosted on AWS and uses Business Critical or higher.
  • Your Snowflake account is in the same AWS Region as your Dremio organization. See Regions.
  • You can use the ACCOUNTADMIN role in Snowflake.
  • You can open a request with Snowflake Support. Snowflake requires a support-assisted authorization flow for managed cloud service and third-party vendor AWS account identifiers.

Review Snowflake's documentation for private connectivity for inbound network traffic, AWS PrivateLink and Snowflake, and SYSTEM$GET_PRIVATELINK_CONFIG() before you proceed.

Complete these steps in order. You perform the Snowflake authorization steps and provide the Snowflake PrivateLink configuration values. Dremio Support notifies you when the PrivateLink connection has been created.

Step 1: Validate the Snowflake Account​

Validate the Snowflake account before you open a support request. This confirms your account is eligible and avoids endpoint creation failures later in the process.

  1. Open the Snowflake console.
  2. Confirm that the Snowflake account is hosted on AWS.
  3. Confirm that the Snowflake account uses Business Critical or higher.
  4. Confirm that you can use the ACCOUNTADMIN role.
  5. Record the AWS Region where the Snowflake account is hosted. You will provide this to Dremio in Step 5.

Step 2: Open a Dremio Support Request​

Open a request with Dremio Support to start the private source connectivity workflow. Include the Dremio organization and project that need access to Snowflake.

  1. Go to the Dremio Support Portal.
  2. Request private source connectivity for Snowflake through AWS PrivateLink.
  3. Provide your Dremio Organization ID.
  4. Request the Dremio AWS account ID that Snowflake must authorize.

Dremio will respond with the following values, which you need to complete Step 3.

ValueDescription
Dremio AWS account ID or IDsThe AWS account identifiers that Snowflake must authorize for AWS PrivateLink connectivity.
AWS RegionThe AWS Region where Dremio creates the interface VPC endpoint.

Step 3: Request Snowflake Authorization for Dremio​

Ask Snowflake Support to authorize the Dremio AWS account ID for AWS PrivateLink to your Snowflake account. Snowflake requires this support-assisted flow for managed cloud services and third-party vendors.

Provide Snowflake Support with the following details:

  • Your Snowflake account identifier.
  • The Snowflake account region.
  • The Dremio AWS account ID.
  • A request to authorize the Dremio AWS account ID for AWS PrivateLink to the Snowflake Service.

After Snowflake confirms authorization, use the ACCOUNTADMIN role to get the Snowflake PrivateLink configuration values.

Get Snowflake PrivateLink configuration 
USE ROLE ACCOUNTADMIN;
SELECT SYSTEM$GET_PRIVATELINK_CONFIG();

Record the following values to provide to Dremio in Step 5.

ValueDescription
privatelink-vpce-idThe Snowflake-provided value that Dremio uses to create the AWS VPC endpoint.
privatelink-account-urlThe Snowflake PrivateLink hostname for the account connection.
privatelink-ocsp-urlThe Snowflake PrivateLink OCSP hostname for certificate status checks.

After the Snowflake authorization is active, return the values that Dremio needs to create the endpoint and private DNS records. Use the same Dremio Support request or your approved secure channel.

Return the following values to Dremio:

  • privatelink-vpce-id
  • privatelink-account-url
  • privatelink-ocsp-url

Step 6: Configure the Snowflake Connection in Dremio​

After Dremio Support confirms that the PrivateLink connection has been created, configure the Snowflake source in Dremio. For source configuration steps, see Connect to Snowflake.

Coordinate removal with Dremio before you remove Snowflake authorization. Dremio must remove the VPC endpoint, private DNS records, and private source configuration from Dremio infrastructure.

  1. Open a Dremio Support request to remove the Snowflake private source connection.
  2. Wait for Dremio to confirm that the VPC endpoint, private DNS records, and private source path are removed.
  3. Ask Snowflake Support to remove authorization for the Dremio AWS account ID or IDs if you no longer need the PrivateLink path.

Predicate Pushdowns​

These operations and functions are performed by Snowflake warehouses:

||, AND, OR
+, -, /, *
<=, <, >, >=, =, <>, !=
ABS
ADD_MONTHS
AVG
BETWEEN
CASE
CAST
CEIL
CEILING
CHARACTER_LENGTH
CHAR_LENGTH
COALESCE
CONCAT
COUNT
COUNT_DISTINCT
COUNT_DISTINCT_MULTI
COUNT_FUNCTIONS
COUNT_MULTI
COUNT_STAR
DATE_ADD
DATE_SUB
DATE_TRUNC
DATE_TRUNC_DAY
DATE_TRUNC_HOUR
DATE_TRUNC_MINUTE
DATE_TRUNC_MONTH
DATE_TRUNC_QUARTER
DATE_TRUNC_WEEK
DATE_TRUNC_YEAR
DAYOFMONTH
DAYOFWEEK
DAYOFYEAR
EXTRACT
FLOOR
ILIKE
IN
IS DISTINCT FROM
IS NOT DISTINCT FROM
IS NOT NULL
IS NULL
LAST_DAY
LEFT
LENGTH
LIKE
LOCATE
LOWER
LPAD
LTRIM
MAX
MEDIAN
MIN
MOD
NOT
PERCENT_CONT
PERCENT_DISC
PERCENT_RANK
POSITION
REGEXP_LIKE
REPLACE
REVERSE
RIGHT
ROUND
RPAD
RTRIM
SIGN
SQRT
STDDEV
STDDEV_POP
STDDEV_SAMP
SUBSTR
SUBSTRING
SUM
TO_CHAR
TO_DATE
TRIM
TRUNC
TRUNCATE
UPPER