One thing to watch out for is the "norms" overhead which is one byte per field, per document. These are byte arrays used in scoring to account for the length of fields in individual documents. With hundreds of fields and millions of documents this can eat up memory.
The good news is you can opt to omit norms for a choice of field or if you have specify indexed field as untokenized. Cheers, Mark ----- Original Message ---- From: "Dai, Chunhe" <[EMAIL PROTECTED]> To: java-user@lucene.apache.org Sent: Thursday, 3 January, 2008 4:45:05 PM Subject: Suggested number of fields limit per Index I have been searching online could not find an exact answer; and wondering if anyone here knows whether there is a preferred max number of fields limit in lucene index? We are in the process of deciding how our index would look like in our lucene integration. For one of our approach, we could have a large number of fields in the index - say maybe several hundred. But, each Document in the index do not contain every of those fields and would only have a few fields within those hundreds of fields (Probably in tens). Does anyone ever have experience with set up like this? I am wondering whether there is a potential performance issue with indexing and searching. Thanks. Chunhe --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] ___________________________________________________________ Support the World Aids Awareness campaign this month with Yahoo! For Good http://uk.promotions.yahoo.com/forgood/ --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]