Google BigQuery

Dremio supports connecting to Google BigQuery as an external source. The connector uses Google Service Account Keys as the authentication method. To know more about creating service account keys, see Create and delete service account keys.

Configuring Google BigQuery 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 Google BigQuery.

General

1. In the Name field, specify the name by which you want the Google BigQuery source to appear in the list of data sources. The name cannot include the following special characters: /, :, [, or ].

2. Under Connection, follow these steps:

   1. In the Host field, specify the URL for the Google BigQuery source.
   2. In the Port field, specify the port to use. The default port is 443.
   3. In the Project Id field, specifiy the Google Cloud Project ID.

3. Under Authentication, specify the service account Client Email and the Service Account Key (JSON).

   note

   This connector assumes that the Service Account Key is a JSON Web Key. For more information on Google Cloud service account credentials, please see Service account credentials.

Advanced Options

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

Option	Description
Record fetch size	Number of records to fetch at once. Set to 0 (zero) to have Dremio automatically decide. By default, this is set to 200.
Maximum Idle Connections	The total number of connections allowed to be idle at a given time. The default number of 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 6 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. Set the Query timneout to 0 for no timeout. The default Query timeout is 0.

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, otherwise, the default is to refresh automatically.
Refresh every	How often to refresh reflections, specified in hours, days or weeks. This option is ignored if Never refresh is selected.
Set refresh schedule	Specify the daily or weekly schedule.
Never expire	Select to prevent reflections from expiring, otherwise, the default is to expire automatically after the time limit specified in Expire after.
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

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.
  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 tab, you can grant privileges to specific users or roles. See Access Control for additional information about privileges.

note

All privileges are optional.

1. 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/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.

Updating a Google BigQuery Source

To update a Google BigQuery source:

1. On the Datasets page, under Databases in the panel on the left, find the name of the source you want to update.
2. Right-click the source name and select Settings from the list of actions. Alternatively, click the source name and then the at the top right corner of the page.
3. In the Source Settings dialog, edit the settings you wish to update. Dremio does not support updating the source name. For information about the settings options, see Configuring Google BigQuery as a Source.
4. Click Save.

Deleting a Google BigQuery Source

note

If the source is in a bad state (for example, Dremio cannot authenticate to the source or the source is otherwise unavailable), only users who belong to the ADMIN role can delete the source.

To delete a Google BigQuery source, perform these steps:

1. On the Datasets page, click Sources > Databases in the panel on the left.

2. In the list of data sources, hover over the name of the source you want to remove and click to the right.

3. From the dropdown, select Delete.

4. In the Delete Source dialog, click Delete to confirm that you want to remove the source.

   caution

   Deleting a source causes all downstream views that depend on objects in the source to break.

   note

   Sources containing a large number of files or tables may take longer to be deleted. During this time, the source name is grayed out and shows a spinner icon, indicating the source is being deleted. Once complete, the source disappears.

Predicate Pushdowns

Dremio pushes the following operations to Google BigQuery.

*, +, -, /, %
<, <=, <>, =, >, >=, !=
AND, NOT, OR, ||
ABS
ACOS
ADD_MONTHS
ASIN
ATAN
ATAN2
AVG
CAST
CEIL
CEILING
CHAR_LENGTH
CHARACTER_LENGTH
CONCAT
COS
COT
DATE_ADD
DATE_SUB
DATE_TRUNC_DAY
DATE_TRUNC_HOUR
DATE_TRUNC_MINUTE
DATE_TRUNC_MONTH
DATE_TRUNC_YEAR
DEGREES
E
EXP
EXTRACT_DAY
EXTRACT_DOW
EXTRACT_DOY
EXTRACT_HOUR
EXTRACT_MINUTE
EXTRACT_MONTH
EXTRACT_QUARTER
EXTRACT_SECOND
EXTRACT_WEEK
EXTRACT_YEAR
FLOOR
IS DISTINCT FROM
IS NOT DISTINCT FROM
IS NOT NULL
IS NULL
LAST_DAY
LCASE
LEFT
LENGTH
LIKE
LN
LOCATE
LOG
LOG10
LOWER
LPAD
LTRIM
MAX
MEDIAN
MIN
MOD
MONTH
PERCENT_CONT
PERCENT_DISC
PI
POSITION
POW
POWER
RADIANS
RAND
REPLACE
REVERSE
RIGHT
ROUND
RPAD
RTRIM
SIGN
SIN
SQRT
SUBSTR
SUBSTRING
SUM
TAN
TIMESTAMPADD_DAY
TIMESTAMPADD_HOUR
TIMESTAMPADD_MINUTE
TIMESTAMPADD_MONTH
TIMESTAMPADD_QUARTER
TIMESTAMPADD_SECOND
TIMESTAMPADD_YEAR
TIMESTAMPDIFF_DAY
TIMESTAMPDIFF_HOUR
TIMESTAMPDIFF_MINUTE
TIMESTAMPDIFF_MONTH
TIMESTAMPDIFF_QUARTER
TIMESTAMPDIFF_SECOND
TIMESTAMPDIFF_WEEK
TIMESTAMPDIFF_YEAR
TO_DATE
TRIM
TRUNC
TRUNCATE
UCASE
UPPER
YEAR