Delete DB table

This step provides the ability to read data from a delimited file. The CSV label for this step is a misnomer because you can define whatever separator you want to use, such as pipes, tabs, and semicolons; you are not constrained to using commas. Internal processing allows this step to process data quickly. Options for this step are a subset of the Text File Input step.

Parameters are associated with local variables in the transformation or job.

This step allows you to get the value of a variable. This step can return rows or add values to input rows.

You must specify the complete variable specification in the format ${variable} or %%variable%% (as described in Variables) . That means you can also enter complete strings in the variable column, not just a variable.

For example, you can specify: ${java.io.tmpdir}/kettle/tempfile.txt and it will be expanded to /tmp/kettle/tempfile.txt on Unix-like systems. To convert the Variable into a data type other than String use Select Values - Meta Data tab. To get system values, including command line arguments, use the Get System Info step.

The Delete step functions by taking input rows from previous steps in your transformation and using their field values to construct SQL DELETE statements. For each incoming row, it identifies which records to delete by matching the key fields you specify with the corresponding columns in your target database table. This step doesn't require all fields from the table to be present in the input stream - only the key fields needed to uniquely identify records for deletion are necessary.

When configuring the Delete step, you need to specify the target database connection, the table to delete from, and the key fields that will be used to match records. You can also set batch size parameters to optimize performance for bulk operations. The step provides options for commit size, allowing you to control transaction boundaries when deleting large volumes of data.

When the transformation runs, the Delete step takes each incoming row, extracts the values from the specified key fields, and uses them to create and execute a DELETE statement against the target database. The step doesn't pass any rows downstream in the transformation flow - it's considered a terminal step.

This step is commonly used in data maintenance operations, data cleansing workflows, or when implementing slowly changing dimensions in data warehousing.