How does the format of my data affect indexing?

Answer: You can expect much lower storage overhead for formatted documents such as Microsoft Word files because the documents tend to be very large compared to the actual text held in them. So 1 GB of Word documents might only require 50 MB of index space, whereas 1 GB of plain text might require 500 MB, because there is ten times as much plain text in the latter set.

Indexing time is less clear-cut. Although the reduction in the amount of text to be indexed has an obvious effect, you must balance this against the cost of filtering the documents with the AUTO_FILTER filter or other user-defined filters.