Pre processors enable the users to add Flink operators/transformations before passing on the stream to the SQL query. Each stream registered on dagger can have chained pre processors. They will run and transform the data before SQL processing.

Currently, there is only one type of pre-processor.

A list of transformer configs.

Table name for the transformer.

List of transformers per table.

Fully qualified name of the class to be used for transformation.

A key-value map required for parameters required for the custom transformation class.

FLINK_SQL_QUERY = "SELECT data_1, data_2, event_timestamp from data_stream"PROCESSOR_PREPROCESSOR_ENABLE = truePROCESSOR_PREPROCESSOR_CONFIG = {  "table_transformers": [{    "table_name": "data_stream",    "transformers": [{      "transformation_class": "InvalidRecordFilterTransformer"    }]  }]}