It is really a hard job to complete settle up a information management system in a large organizations. It requires several strategies, planning and implementation to work in the most perfect, useful and reliable way. Transactional systems keep bulk of data which are associated with the already developed systems of an organization. For example it is associated with the sales and purchases transactions software.
To build a data warehouse, ETL or Extract, Transform and Load are the most essential things which are needed to be employed at every cost. There are many processes which are required to be fulfill in order to completely build an ETL (Extract, Transform, Load).
Extract: Extraction means the extraction of data from developed system of data storages. Authorized entities extract data for their required or demanded purpose. Extraction is done from thousands of IT systems placed in a pool. Extraction of a similar data can be made from multiple system. For example a data related to some purchase and sales transactions may be recorded on many computers. The data warehouse will determine from where to extract the data. The extractor can also specify from where to extract the required data.
Transform: Once the data has been extracted, it needs to be converted into information in order to be useful for the user. The process of converting data into useful information is called as ‘transform’ and it comprises big portion of engineering required to setup a data warehouse. Also, when the data is extracted for a particular system, it is checked. If the data is correct and meets the called requirements, then it is forward to the transform step otherwise it revert back with an appropriate error. If transformation is done from multiple systems, then converting of data into useful information will also go through several procedures as different computer systems will have the same data in different formatting. This formatting is also done by the transform step and you get the information from all of the desired or called system according to your needs.
There is also a big amount of data in data ware house which is not capable of being used as information. It is essential to discard this data at every cost at it can also creates confusion for the user in addition with the useful data. Therefore, several systems are employed in between to filter out the unnecessary and discarded data.
Load: Load is the loading of the called data after being converted into information in the called system or end target. This end target is usually the data warehouse. The process of loading data can vary greatly from one system to other system and from one organization to other organization. The processes vary on the basis of the requirements of the organizations. Some very complex system can keep records of all the things including each and every part of data that is being loaded in the data warehouse.
Finally, from cycle initialization to the clean up, there exist a highly sophisticated system with lot of engineering and information management techniques.