• Explanation

Migrating data from different systems to a centralized location (ie, data repository) so the data can be analyzed for business intelligence purposes requires a three-step process called extract, transform, load (ETL)Three-step process of gathering data from different systems, sanitizing and converting the data into a useable format, then loading it into a centralized target database.. The loading phase Final extract, transform, load phase that inserts transformed data into the target database for analysis. involves inserting the transformed data into the target database (eg, data warehouse) for further analysis.

There are three ways to load data:

• Initial load: An initial load is used when loading all the data originally extracted and transformed into the target database for the first time. It is not an update function (Choice D).
• Incremental loading: After the initial data is loaded, incremental loads update only the data that has been modified, added, or deleted. Newly extracted and transformed data is compared with the existing target database to produce additional or modified records (Choices B and C).
• Full refresh: This process erases and replaces the entire target database. This function is used if the entity cannot identify which data has been changed since the prior load.

Things to remember:
Loading, the final extract, transform, load phase, inserts transformed data into the target database for data analysis. There are three types of data loading: initial load, incremental loading, and full refresh. After the initial load, if the organization is unable to determine which data has been modified, added, or deleted since the prior data load, only a full refresh can be used.