Microsoft SQL Server
Microsoft SQL Server is a database server for storing and retrieving data, and this topic describes how to configure a SQL Server database as a Dremio Sonar source.
Prerequisites
Ensure that you have the following details before configuring SQL Server as a source:
- Hostname or IP address of the database
- Port
- Ensure that the database version is SQL Server version 2012 or later.
Dremio SQL Server Configuration
Perform these steps to configure SQL Server as a source:
In the Datasets UI, you can see a truncated list of Sources at the bottom-left of the page. Click + Add Source.
Alternatively, click Databases. The page displays all database sources. Click the Add database button at the top-right of that page.
In the Add Data Source dialog, click Microsoft SQL Server.
The following section describes the source configuration tabs.
General
The General tab contains the required fields to create a SQL Server source.
Perform these steps in the General tab:
- In the General tab, for Name, enter a name.
- For Host, enter the SQL Server host name.
- For Port, enter the SQL Server port number. The default port is 1433.
- (Optional) For Database, enter the SQL Server database name.
- (Optional) For Encrypt connection, enable encrypted connections to SQL Server using SSL.
- For Authentication, Master Authentication is the default and the only option. Provide the username and password of a master database user with permissions to read required objects:
- For Username, enter your SQL Server database username.
- For Password, enter your SQL Server database password.
Advanced Options
Click Advanced Options in the sidebar.
note:
All advanced options are optional.
Advanced Option | Description |
---|---|
Show only the initial database used for connecting | If selected, hides the other databases that the credential has access to. |
Record fetch size | Number of records to fetch at once. Set to 0 (zero) to have Sonar automatically decide. The default record fetch size is 200. |
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. |
Encryption | Verify Server Certificate is enabled. Add an SSL/TLS server certificate distinguished name in the text box. |
Connection Properties | Custom key value pairs for the connection relevant to the source. To add a connection property, click Add property and add the property name and value. |
Reflection Refresh
The Reflection Refresh tab in the sidebar allows you to set time intervals for reflections to refresh or expire.
Metadata
You can configure settings to refresh metadata and handle datasets. Click Metadata in the sidebar.
You can configure Dataset Handling and Metadata Refresh parameters.
Dataset Handling
These are the Dataset Handling parameters.
note:
All Dataset Handling parameters are optional.
Parameter | Description |
---|---|
Remove dataset definitions if underlying data is unavailable | By default, Sonar 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 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 Sonar needs for query planning such as information required for fields, types, shards, statistics, and locality. These are the parameters to fetch the dataset information.
note:
All Dataset Details parameters are optional.
Parameter | Description |
---|---|
Fetch mode | You can choose to fetch only from queried datasets that are set by default. Sonar 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
You can grant privileges to specific users or roles.
- (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.
- (Optional) For the users or roles in the Users table, toggle the green checkmark for each privilege you want to grant to the SQL Server source that is being created.
Click Save after setting the configuration.
Editing a SQL Server Source
To edit a SQL Server source:
- In the Datasets UI, click Databases. A list of databases is displayed.
- Under the Actions column, click the Settings (gear) icon for the source you want to edit. From the list of actions, click Edit Details.
- In the Edit Source dialog, you cannot edit the name. Editing other parameters is optional.
- Click Save.
Removing a SQL Server Source
To remove a SQL Server source, perform these steps:
- In the Datasets UI, click Databases. A list of sources is displayed.
- Under the Actions column, click the Settings (gear) icon for the source that you want to remove.
- From the list of actions, click Remove Source. Confirm that you want to remove the source.
warning:
Removing a source causes all downstream views dependent on objects in this source to break.
Predicate Pushdowns
Dremio offloads these operations to SQL Server.
Operators | Operators | Operators | Operators |
---|---|---|---|
*, +, -, /, % | E | LOWER | TAN |
<, <=, <>, =, >, >=, != | EXP | LPAD | TIMESTAMPADD_DAY |
AND, NOT, OR, || | EXTRACT_DAY | LTRIM | TIMESTAMPADD_HOUR |
ABS | EXTRACT_DOW | MAX | TIMESTAMPADD_MINUTE |
ACOS | EXTRACT_DOY | MIN | TIMESTAMPADD_MONTH |
ASIN | EXTRACT_HOUR | MOD | TIMESTAMPADD_QUARTER |
ATAN | EXTRACT_MINUTE | MONTH | TIMESTAMPADD_SECOND |
ATAN2 | EXTRACT_MONTH | PI | TIMESTAMPADD_YEAR |
AVG | EXTRACT_QUARTER | POSITION | TIMESTAMPDIFF_DAY |
CAST | EXTRACT_SECOND | POW | TIMESTAMPDIFF_HOUR |
CEIL | EXTRACT_WEEK | POWER | TIMESTAMPDIFF_MINUTE |
CEILING | EXTRACT_YEAR | RADIANS | TIMESTAMPDIFF_MONTH |
CHAR_LENGTH | FLOOR | RAND | TIMESTAMPDIFF_QUARTER |
CHARACTER_LENGTH | IS DISTINCT FROM | REPLACE | TIMESTAMPDIFF_SECOND |
CONCAT | IS NOT DISTINCT FROM | REVERSE | TIMESTAMPDIFF_WEEK |
COS | IS NOT NULL | RIGHT | TIMESTAMPDIFF_YEAR |
COT | IS NULL | ROUND | TO_DATE |
DATE_ADD | LCASE | RPAD | TRIM |
DATE_SUB | LEFT | RTRIM | TRUNC |
DATE_TRUNC_DAY | LENGTH | SIGN | TRUNCATE |
DATE_TRUNC_HOUR | LIKE | SIN | UCASE |
DATE_TRUNC_MINUTE | LN | SQRT | UPPER |
DATE_TRUNC_MONTH | LOCATE | SUBSTR | YEAR |
DATE_TRUNC_YEAR | LOG | SUBSTRING | |
DEGREES | LOG10 | SUM |
NOTE: Since SQL Server has no boolean type, project operations that contain SQL expressions which evaluate to true or false (e.g. SELECT username, friends > 0
), and filter operations that include boolean literals in a filter (e.g. WHERE currentAccount = true
) cannot be executed as pushdowns.