1. A computer-implemented method of managing performance of data integration comprising: receiving data about the data integration job execution, wherein the data integration job is for an extract, transform, and load (ETL) job; determining whether there is a performance issue of the data integration job execution; analyzing the data about the data integration job execution when there is a performance issue; generating and implementing a job execution design recommendation based on analyzing the data and a set of predefined recommendation rules, wherein the set of predefined recommendation rules comprises an operator combining recommendation, wherein the operator combining recommendation specifies that the processes of two or more operators are to be carried out by a single operator; and displaying the data about the data integration job execution and when there is a generated job execution design recommendation, displaying the job execution design recommendation, wherein the displaying the data of the data integration job includes displaying an execution plan of a designed job execution and a process view of one or more processes of an actual job execution.