I think it would depend on whether the cache key's are independant of IndexReaders (i.e. an implementation that's not implemented in the same manner as the QueryFilter by using an IndexReader as a cache key (or part thereof). This is because I open multiple IndexReaders against a single index which would cause (false) cache misses.
Why do you open multiple IndexReaders against a single index? Ordinarily I would only expect an application to open a new index reader when the index has changed, or in order to do deletions. In both of these cases, the cache would work correctly.
Note that an open index reader uses much more memory than another bit vector in a cache will. It caches a byte per document for each field you've searched, plus 1/128th of all the terms in the index. So, e.g., the cached bit vectors could become dominant if you use more than eight caches and only search a single field.
Doug
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
