What is source to target mapping in ETL?
A document that contains the mapping of source system fields to the fields of a target system. In a data warehouse, this will typically be a mapping from either source files or database tables to the respective tables in your target data warehouse / data mart. The STTM document is the blueprint of your ETL solution.
What are ETL Tester responsibilities?
An ETL tester is primarily responsible for validating the data sources, extraction of data, applying transformation logic, and loading the data in the target tables.
How do you automate a source to target mapping?
Steps Involved in Source to Target Mapping
- Step 1: Defining the Attributes.
- Step 2: Mapping the Attributes.
- Step 3: Transforming the Data.
- Step 4: Testing the Mapping Process.
- Step 5: Deploying the Mapping Process.
- Step 6: Maintaining the Mapping Process.
What is source and target system?
Source-to-Target mapping is a set of data transformation instructions that determine how to convert the structure and content of data in the source system to the structure and content needed in the target system. Additionally, users can map data values in the source system to the range of values in the target system.
What are the challenges faced in ETL Testing?
The main challenges of ETL or Data warehouse testing includes :
- Data loss during ETL testing.
- Duplicate data and Incompatibility.
- Lack of inclusive test bed.
- Testers have no benefits to execute ETL jobs by their own.
- Data volume and complexity is huge.
- Inefficient in procedures and business process.
How is data quality checked in ETL testing?
Checking data quality during ETL testing involves performing quality checks on data that is loaded in the target system. It includes the following tests − The Number format should be same across the target system.
What are the test cases for the ETL process?
The test cases required to validate the ETL process by reconciling the source (input) and target (Output) data. The transformation rule also specifies that output should only have corporate customers. Physical Test 1: Count the corporate customers from the source. Count the customers from the target table.
What does ETL stand for in data warehouse?
ETL or data warehouse is one of the offerings which are developing rapidly and successfully. Through ETL process, data is fetched from the source systems, transformed as per business rules and finally loaded to the target system (data warehouse).
Which is the standard format for precision in ETL?
For example, it should be same across all the records. The Standard format is: yyyy-mm-dd. Precision value should display as expected in the target table. For example, in the source table, the value is 15.2323422, but in the target table, it should display as 15.23 or round of 15.