Final answer:
Filtering data from a source might not change the size of the extract because the extract's size could be predetermined based on a fixed structure, rather than the actual content size.
Step-by-step explanation:
The question seems to be about data management within a computing or technological context, specifically related to the size of a data extract after filtering data from the data source. When you filter the data from a data source, you are essentially selecting a subset of the entire data set based on certain criteria. This process is intended to discard irrelevant or unnecessary data. However, the size of the extract, which refers to the physical space that the data occupies on a storage device, may not necessarily change after filtering. This could be due to the way the data is structured or how the extract is created. For example, if the extract is created with a fixed structure that allocates space for the potential maximal size of the data, filtering the data might not reduce the allocated size, even though the actual data content is reduced.