User Guide > Streaming Mappings > Transformations in a Streaming Mapping
  

Transformations in a Streaming Mapping

Informatica Developer provides a set of transformations that perform specific functions. Some restrictions and guidelines apply to processing transformations in a streaming mapping.
You can use the following transformations in a streaming mapping:
Aggregator
Mapping validation fails when the
Data Masking
Supported without restrictions.
Expression
Mapping validation fails when the transformation contains unsupported functions in an expression.
If an expression results in numerical errors, such as division by zero or SQRT of a negative number, it returns an infinite or an NaN value. In the native environment, the expression returns null values and the rows do not appear in the output.
Filter
Supported without restrictions.
Java
The following restrictions apply to the Java transformation:
To run user code directly on the Spark engine, the JDK version that the Data Integration Service uses must be compatible with the JRE version on the cluster. For best performance, create the environment variable DIS_JDK_HOME on the Data Integration Service in the Administrator tool. The environment variable contains the path to the JDK installation folder on the machine running the Data Integration Service. For example, you might enter a value such as /usr/java/default
You can use complex data types to process hierarchical data.
Note: The complex data type support for the Java transformation is available for technical preview. Technical preview functionality is supported but is unwarranted and is not production-ready. Informatica recommends that you use in non-production environments only.
For more information about Java transformation support on the Spark engine, see the Informatica Big Data Management User Guide.
Joiner
Mapping validation fails in the following situations:
Lookup
Use a Lookup transformation to look up data in a flat file, HDFS, Hive, or Sqoop and perform an uncached lookup on HBase data.
Mapping validation fails in the following situations:
The mapping fails in the following situations:
You cannot use a float data type to look up data in a Hive table as comparing equality of floating point numbers is unsafe.
When you configure the transformation to return the first, last, or any value on multiple matches, the Data Integration Service returns any value.
To use a Lookup transformation on Sqoop in a Cloudera distribution, perform the following configuration:
  1. 1. In the Yarn configuration, locate the property NodeManager Advanced Configuration Snippet (Safety Valve) for mapred-site.xml
  2. 2. Add the following xml snippet:
  3. <property>
    <name>mapreduce.application.classpath</name>
    <value>$HADOOP_MAPRED_HOME/,$HADOOP_MAPRED_HOME/lib/,
    $MR2_CLASSPATH</value>
    </property>
Note: Informatica recommends that you select the Ignore null values that match property in Lookup transformation advanced properties to avoid cross join of DataFrames.
To use a Lookup transformation on uncached HBase tables, perform the following steps:
  1. 1. Create an HBase data object. When you add an HBase table as the resource for a HBase data object, include the ROW ID column.
  2. 2. Create a HBase read data operation and import it into the streaming mapping.
  3. 3. When you import the data operation to the mapping, select the Lookup option.
  4. 4. In the Lookup tab, configure the following options:
  5. 5. Verify that format for any date value in the HBase tables is of a valid Java date format. Specify this format in the Date Time Format property of the Advanced Properties tab of the data object read operation.
Mapping validation fails in the following situations:
Normalizer
Supported without restrictions.
Python
Supported without restrictions.
Note: The Python transformation is available for technical preview. Technical preview functionality is supported but is unwarranted and is not production-ready. Informatica recommends that you use in non-production environments only.
Rank
Mapping validation fails if case-sensitivity is disabled.
Router
Supported without restrictions.
Sorter
To use the Sorter transformation in a Streaming mapping, configure the following properties:
Mapping validation fails in the following situations:
The Data Integration Service logs a warning and ignores the Sorter transformation in the following situations:
The Data Integration Service treats null values as high even if you configure the transformation to treat null values as low.
Union
Supported without restrictions.
Window
Supported without restrictions.
See the Window Transformation chapter in this guide for more information.
Transformations that are not listed here are not supported.
For more information about the transformations, see the Informatica Developer Transformation Guide.
For more information about transformation support on the Spark engine, see the Informatica Big Data Management User Guide.