A sample package
Data transformation is represented as a directed graph which consists of reading/writing/transforming blocks (nodes) linked by directed edges - arrows. Data records flow according to arrow directions and a method of blocks operation.
A single flow is called package and it is treated as a procedure to be called from the outside.

While running a package, the following information is displayed on a graph which represents a single data flow:
- a number of records which passed through given operations,
- a percentage of transformed data.
This information is a summary of task execution after the process is finished.
