Dremio Cloud
Dremio Software
 
On this page

    Snowflake

    Snowflake is a cloud data warehouse.

    Configuring Snowflake as a Source

    1. In the bottom-left corner of the Datasets page, click Add Source.
    2. Under Databases in the Add Data Source dialog, select Snowflake.

    General

    1. In the Name field, specify the name by which you want the Snowflake source to appear in the Databases section.
    2. Under Connection, follow these steps:
      1. In the Host field, specify the account URL of the Snowflake source in the format https://LOCATOR_ID.snowflakecomputing.com.
      2. (Optional) In the Database field, specify the default database to use.
      3. (Optional) In the Role field, specify the default access-control role to use.
      4. (Optional) In the Schema field, specify the default schema to use.
      5. (Optional) In the Warehouse field, specify the warehouse that will provide resources for executing DML statements and queries.
    3. Under Authentication, specify the username and password for Dremio to use when connecting to the Snowflake source.

    Advanced

    On the Advanced Options page, you can set values for these non-required options:

    Option Description
    Maximum Idle Connections The total number of connections allowed to be idle at a given time. The default maximum idle connections is 8.
    Connection Idle Time The amount of time (in seconds) allowed for a connection to remain idle before the connection is terminated. The default connection idle time is 60 seconds.
    Query Timeout The 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.

    Option Description
    Never refresh Select to prevent automatic reflection refresh, default is to automatically refresh.
    Refresh every How often to refresh reflections, specified in hours, days or weeks. This option is ignored if Never refresh is selected.
    Never expire Select to prevent reflections from expiring, default is to automatically expire after the time limit below.
    Expire after The 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.

    Parameter Description
    Remove dataset definitions if underlying data is unavailable By 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 source object names such as databases and tables. Set the time interval using this parameter.
    Parameter Description
    (Optional) Fetch every You can choose to set the frequency to fetch object names in minutes, hours, days, or weeks. The default frequency to fetch object names 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.
    Parameter Description
    Fetch mode You can choose to fetch only from queried datasets that are set by default. Dremio updates details for previously queried objects in a source. Fetching from all datasets is deprecated.
    Fetch every You can choose to set the frequency to fetch dataset details in minutes, hours, days, or weeks. The default frequency to fetch dataset details is 1 hour.
    Expire after You can choose to set the expiry time of dataset details in minutes, hours, days, or weeks. The default expiry time of dataset details is 3 hours.

    Privileges

    On the Privileges page, you can grant privileges to specific users or roles. See Access Controls for additional information about user privileges.

    1. (Optional) For Privileges, enter the user name 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 table.
    2. (Optional) For the users or roles in the Users table, toggle the green checkmark for each privilege you want to grant on the Dremio source that is being created.
    3. Click Save after setting the configuration.

    Editing a Snowflake Source

    To edit a Snowflake source:

    1. On the Datasets page, click External Sources at the bottom-left of the page. A list of sources is displayed.

    2. Hover over the external source and click the Settings This is the icon that represents the Source settings. icon that appears next to the source.

    3. In the Source Settings dialog, you cannot edit the name. Editing other parameters is optional. For parameters and advanced options, see Configuring Snowflake as a Source.

    4. Click Save.

    Removing a Snowflake Source

    To remove a Snowflake source, perform these steps:

    1. On the Datasets page, click External Sources at the bottom-left of the page. A list of sources is displayed.

    2. Hover over the the source and click the More (…) icon that appears next to the source.

    3. From the list of actions, click Remove Source. Confirm that you want to remove the source.

    warning:

    Removing a source causes all downstream virtual datasets dependent on objects in this source to break.

    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