InformaticaETL tools and update are an important feature of ETL tools. Because of this, we will find that the update settings are available in many parts of the Informatica tool. In many cases, it has caused a lot of confusion for everyone. I don't know who is the first and who is the first, who has a high priority or what the specific role is, I hope to share this article with you a clear concept.
Informatica Of The update process simply refers to the process of setting a delete, insert, update, or reject flag for each data record. We collectively refer to the process of setting the update flag bit and finally schedule it.ProgramUpdate operations are performed based on the flag. The following is a detailed description of the Flag setting sequence.
- Init
For any Each data entry of mapping, which is marked as insert by default. That is, if there is no operation to change the flag, this data will be inserted.
- InUpdate strategy is used in mapping.
When When update strategy is used in mapping, You can change the updated flag value from Change Insert to update, insert, and delete.
- Treat source rows
In In session attribute settings, you can set the value of treat source rows as to update the flag again. That is to say, no matter what update flag is set in mapping, you can make another change. If the insert, update, and delete methods are selected, the update flag is changed to insert, update, and delete, regardless of how the update flag is modified in mapping. When data driven is selected, the system will not modify the flag bit to maintain the original flag value.
- Target Properties
The last one that has an impact on updates is Target attribute settings. Its initial default setting is shown in the figure, The insert, update as update, and delete options are selected. This is what we call the basis for final scheduling. The three selected options by default indicate that when the session is running, the insert flag is met, that is, the insert operation is performed, and the update operation is performed when the update flag is met, when the delete mark is reached, the delete operation is performed. Of course, we can cancel the hook. In this way, the data with the corresponding flag will not be processed during the Informatica operation. For example, if you cancel the insert check, during the session operation, no operation will be performed on all data marked as insert. Here, we need to explain in particular Update method, which can be selected in three ways. Here we will provide a detailed description of these three methods. First, we must note that The three methods are mutually exclusive, that is, only one can be selected at the same time. Update as update: for all Update data. Update as insert: Insert operations on all data marked as update Do not Update operation Update else insert: for all Update Data first, Then After successful update, insert the data. For example: Assume that The three pieces of data are set as the update flag in the previous step, and our target properties is set as update else insert. How can we run Informatica at this time. Data 1, 2, 3 will first perform the update operation, while 1, 2 will find the corresponding data based on the primary key for the update, and 3 will not find, the update will fail, and then for 3, informatica will perform the insert operation. The final result is Finally, we can use a diagram to describe The whole update process of Informatica: During initialization, our update flag is set Insert, and the second and third steps can change the flag bit. That is to say, all the three steps above are a flag bit setting process.
The last step is the specific operation. Depending on the settings, the execution process is executed in several different ways..
