Microsoft Azure Synapse Analytics

Dremio supports integrations with organizations using Azure Synapse Analytics dedicated SQL pools via the external source.

Requirements

• Dremio v19.3+

Source Dialog

General tab

The following options are available from the General tab.

• Name - A name to identify the data source in Dremio.
• Connection
  • Host - The URL for your dedicated SQL pool, which typically ends in .sql.azuresynapse.net.
  • Port - The port required to access the data source.
  • Database (optional) - The database's name. Only this database is accessed by Dremio.
• Authentication
  • No Authentication - Dremio does not attempt to provide any authentication when connecting with the SQL pool.
  • Master Credentials - Dremio must provide a specified username and password in order to access the SQL pool.
    • Username - The username with sufficient privileges to perform read/write actions on the SQL pool.
    • Password - The password associated with the username.
  • Encrypt connection - The connection is attempted using HTTPS encryption if enabled.

Advanced Options tab

The following settings control more advanced functionalities in Dremio.

• Advanced Options
  • Show only the initial database used for connecting - This restricts Dremio's access only to a default database as specified on the General table.
  • Record fetch size - Number of records to fetch at once. Set to 0 (zero) to have Dremio automatically decide. The default value is 10.
  • Maximum idle connections - The maximum number of idle connections to keep.
  • Connection idle time (s) - Idle time, in seconds, before a connection is considered for closure.
  • Query timeout (s) - The timeout, in seconds, for query execution before it is canceled. Set to 0 for no timeout.
• Encryption
  • Verify server certificate - Forces Dremio to verify the server's certificate using the distinguished name.
  • SSL/TLS server certificate distinguished name - Specifies the location for the certificate server, which must be set to *.sql.azuresynapse.net.
• Connection Properties
  • Name - The unique name for any custom properties.
  • Value - The value associated with the custom property.

Reflection Refresh tab

This tab controls the frequency of reflection refreshes or the timespan for expiration for any queries performed using this data source.

• Never refresh - Prevents any query reflections associated with this source from refreshing.
• Refresh every - Sets the time interval by which reflections for this source are refreshed. This may be set to hours, days, and weeks.
• Never expire - Prevents any query reflections associated with this source from expiring.
• Expire after - Sets the time after a reflection is created that it then expires and can no longer be used for queries. This may be set to hours, days, and weeks.

Metadata tab

This tab offers settings that control how dataset details are fetched and refreshed.

• Dataset Handling
  • Remove dataset definitions if underlying data is unavailable - If this box is not checked and the underlying files under a folder are removed or the folder/source is not accessible, Dremio does not remove the dataset definitions. This option is useful in cases when files are temporarily deleted and put back in place with new sets of files.
• Metadata Refresh
  • Dataset Discovery
    • Fetch every - Specifies the time interval by which Dremio fetches object names. This can be set by minutes, hours, days, and weeks.
  • Dataset Details
    • Fetch mode - Restricts when metadata is retrieved.
    • Fetch every - Specifies the time interval by which metadata is fetched. This can be set by minutes, hours, days, and weeks.
    • Expire after - Specifies the timespan for when dataset details expire after a dataset is queried. This can be set by minutes, hours, days, and weeks.

Privileges tab

From this tab, administrators may control access to the data source on a user-by-user or group-by-group basis.

For additional information view the Access Control functionality.

Adding Synapse Analytics as a Source

To connect with Azure Synapse Analytics data sources, perform the following steps:

1. From the Dremio console, click the Add button (plus sign) next to the External Sources header from the Home page.
2. Select the source option Microsoft Azure Synapse Analytics.
3. Assign a Name to your source to identify it.
4. Enter the URL Host where your dedicated SQL pool is located (e.g., synapse-test.sql.azuresynapse.net) and the Port (e.g., 1433) set to forward external traffic to the database.
5. If you wish to only use Dremio with a specific dataset, provide its explicit name for Database (e.g., master).
6. To require authenticated access to the data source, select the Master Credentials radio button and then provide the Username and Password with sufficient access to the data source.
7. (Optional) If an encrypted connection is required, select Encrypted connection.
8. (Optional) If a server certificate is required, navigate to the Advanced Options tab, select Verify Server Certificate, and enter *.sql.azuresynapse.net for the SSL/TLS server certificate distinguished name.
9. Click Save to complete the source setup.

Predicate Pushdowns

Dremio delegates the execution of these expressions and functions to the database being queried, often dramatically improving query performance. It can also offload entire SQL queries that include one or more of these expressions and functions.

%, *, +, -, /
<, <=, <>, =, >, >=, !=
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
MIN
MOD
MONTH
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

Running Queries Directly on Azure Synapse Analytics Through Dremio

Dremio users can run pass queries through Dremio to run on Azure Synapse Analytics. Doing so can sometimes decrease query execution times. For more information, see Querying Relational-Database Sources Directly.