Is it possible to have attachments (as Word files) in Endeca ? If yes, where can I find more info about it ? I tried developer's guide, but couldn't find.
Same question with flexfields. Are flexfields supported in Endeca ?
I do not believe flexfields are supported within Endeca. As for importing documents and other types of unstructured data you can use the CAS engine for that. The following link (http://www.endeca123.com/how-to-crawl-web-content-with-the-cas/) provides a good overview of this services. For more details see the following link: http://docs.oracle.com/cd/E29578_01/index.htm
If the Word files are on disk (or on your network somewhere) and not part of a website, you'll want to use CAS File System Crawls, not a CAS Web Crawl.
The Endeca CAS (Content Acquisition System) uses Oracle's OutsideIn document conversion functionality to extract metadata as well as physical contents from a variety of file types (including Microsoft Word, Powerpoint, etc.) and writes them to an Endeca Record Store. You can then read those records out of the record store as part of your Integrator pipeline and bring them in to the Endeca index.
For help creating the File System crawl, you can go here: