Indexing Service questions

[John Croson]

I'm currently using MS Indexing Services on a Windows 2003 server to
index local files. I've a number of iFilters installed to index M$
docs, PDF's, and TIF's.

My users query using Windows Search or a web-based tool I made.

My question is about database limits, or the number of documents
indexed per database.

I have a repository that contains more than 20 million TIF's and text
files.

The database has been building for about a week, and nearly 10 million
have been indexed.

I'm getting concerned about a post I read somewhere that a sysadmin
was experiencing a sudden halt in the indexing at 15 million
documents.

I'm finding that there is sparse documentation about this service, and
was hoping someone with more experience with this could shed some
light on it.

TIA!