tDeltaLakeInput Standard properties
These properties are used to configure tDeltaLakeInput running in the Standard Job framework.
The Standard tDeltaLakeInput component belongs to the Databases family.
The component in this framework is available in all subscription-based Talend products.
If you have installed the 8.0.1-R2023-05 Talend Studio Monthly update or a later one delivered by Talend, this component generates error messages because of the conflicts between Log4j2 and Delta Lake driver. You can prevent such kind of error messages by adding EnableArrow=0 in the JDBC URL field.
Basic settings
| Properties | Description |
|---|---|
| Database |
Select the desired database type from the list and click Apply. |
| Property type |
Either Built-in or
Repository
.
This property is not available when a connection component is selected with the Use an existing connection option. |
| Use an existing connection |
Select this check box and in the Component List drop-down list, select the desired connection component to reuse the connection details you already defined. |
| Schema and Edit Schema |
A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. When you create a Spark Job, avoid the reserved word line when naming the fields. Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:
|
| Guess schema | Click this button to retrieve the schema according to your settings. |
| JDBC URL |
The JDBC URL of the Delta Lake database to be used, which begins with jdbc:spark:// (already presented). If you have installed the 8.0.1-R2023-05 Talend Studio Monthly update or a later one delivered by Talend, the JDBC URL of the Delta Lake database begins with jdbc:databricks// (already presented). See section Configure JDBC URL at JDBC and ODBC drivers and configuration parameters for related information. Information noteNote: There will be no migration operation for Delta Lake components when the 8.0.1-R2023-05
Talend Studio
Monthly update or a later one delivered by Talend
is installed. In this case, you may need to update the JDBC URL and other related
settings manually for existing Jobs to make sure the JDBC URL begins with
jdbc:databricks//.
|
| Drivers |
Complete this table to load the driver JARs needed. To do this, click the [+] button under the table to add as many rows as needed, each row for a driver JAR, then select the cell and click the [...] button at the right side of the cell to open the Module dialog box from which you can select the driver JAR to be used. The driver JAR SparkJDBC42-2.6.14.1018.jar is used for the Delta Lake databases (already presented). If you have installed the 8.0.1-R2023-05 Talend Studio Monthly update or a later one delivered by Talend, the databricks-jdbc-{version_number}.jar driver will be used (already presented). For more information, see Importing a database driver. Information noteNote: There will be no migration operation for Delta Lake components when the
8.0.1-R2023-05 Talend Studio
Monthly update or a later one delivered by Talend
is installed. In this case, you may need to update the driver and other related
settings manually for existing Jobs to make sure
databricks-jdbc-{version_number}.jar is used.
|
| Driver class |
Enter the class name for the specified driver between double quotation marks. For the SparkJDBC42-2.6.14.1018.jar driver, the name to be entered is com.simba.spark.jdbc.Driver (already presented). If you have installed the 8.0.1-R2023-05 Talend Studio Monthly update or a later one delivered by Talend, the databricks-jdbc-{version_number}.jar driver will be used and the driver class to be entered is com.databricks.client.jdbc.Driver (already presented). Information noteNote: There will be no migration operation for Delta Lake components when the
8.0.1-R2023-05 Talend Studio
Monthly update or a later one delivered by Talend
is installed. In this case, you may need to update driver class and other related
settings manually for existing Jobs to make sure the driver class
com.databricks.client.jdbc.Driver is used.
|
| User Id and Password |
The database user authentication data. See section Username and password authentication at JDBC and ODBC drivers and configuration parameters for related information. To enter the password, click the [...] button next to the password field, enter the password in double quotes in the pop-up dialog box, and click OK to save the settings. |
|
Specify a data source alias |
Select this check box and in the Data source alias field displayed, specify the alias of a data source created on Talend Runtime side to use the shared connection pool defined in the data source configuration. This option works only when you deploy and run your Job in Talend Runtime. This property is not available when other connection component is selected from the Connection Component drop-down list. |
|
Table |
Enter the name of the table from which data will be retrieved. |
| Query |
Specify the database query statement paying particularly attention to the sequence of the fields which must correspond to the schema definition.
If using the dynamic schema feature, the SELECT query must include the * wildcard, to retrieve all of the columns from the table selected. This component supports vector search capabilities, you can use this option to specify the query condition using the vector index previously created in Databricks. For more information on vector searches in Databricks, see the corresponding Databricks documentation. |
Advanced settings
| Properties | Description |
|---|---|
|
tStatCatcher Statistics |
Select this check box to gather the Job processing metadata at the Job level as well as at each component level. |
| Use cursor |
Select this check box to specify the number of rows you want to work with at any given time. This option optimises performance. |
|
Trim all the string/CHAR columns |
Select this check box to remove leading whitespace and trailing whitespace from all String/Char columns. |
|
Check column to trim |
Select the check box for corresponding column to remove leading whitespace and trailing whitespace from it. This property is not available when the Trim all the String/Char columns check box is selected. |
| Enable mapping file for dynamic |
Select this check box to use the specified metadata mapping file when reading data from a dynamic type column. This check box is cleared by default. With this check box selected, you can specify the metadata mapping file to use by selecting a type of database from the Mapping File drop-down list. For more information about metadata mapping files, see Accessing mapping files and defining type mappings. |
| Allow special character in dynamic table name |
Select this option to use the actual column names of the input table in the dynamic column. This option prevents special characters (for example, $) in the input table column names from being converted into _ in the dynamic column. This option is selected by default. |
| Use PreparedStatement |
Select this check box if you want to query the database using a prepared statement. In the Set PreparedStatement Parameters table displayed, specify the value for each parameter represented by a question mark ? in the SQL statement defined in the Query field.
For a related use case of this property, see Using PreparedStatement objects to query data. |
| Query timeout |
Select this check box to set a timeout period for the query in seconds. |
Global Variables
| Variables | Description |
|---|---|
|
ERROR_MESSAGE |
The error message generated by the component when an error occurs. This is an After variable and it returns a string. |
|
NB_LINE |
The number of rows processed. This is an After variable and it returns an integer. |
|
QUERY |
The query statement being processed. This is a Flow variable and it returns a string. |
Usage
| Usage guidance | Description |
|---|---|
| Usage rule |
|
| Dynamic settings |
Click the [+] button to add a row in the table and fill the Code field with a context variable to choose your database connection dynamically from multiple connections planned in your Job. This feature is useful when you need to access database tables having the same data structure but in different databases, especially when you are working in an environment where you cannot change your Job settings, for example, when your Job has to be deployed and executed independent of Talend Studio. For examples on using dynamic parameters, see Reading data from databases through context-based dynamic connections and Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic settings and context variables, see Dynamic schema and Creating a context group and define context variables in it. |