Ferret talk - Nov 2006 - Help with Multiple Readers, 1 Writer scenario

Some time back in September, [sorry to be so slow], Dave wrote: 
> When you open an IndexReader on the index it is opened up on 
> that particular version (or state) of the index. So any 
> operations on the IndexReader (like searches) will only show 
> what was in the index at the time you opened it. Any modifications 
> to the index (usually through and IndexWriter) that occur after 
> you open the IndexReader will not appear in your searches. 
> So to keep searches up to date you need to close and reopen your 
> IndexReader every time you commit changes to the index.
Would it be possible to enhance IndexReader to report the "version" of
the index it is using, and to report if a newer version of the index
exists, eg perhaps #version and #current_version?

This would allow a long running IndexReader to detect that a new index
version is available, which is a problem if the IndexWriter updates the
index from another process. For example, I am planning to divide my
application into two apps, one which services reader requests, and the
other which periodically updates the index if needed.

Kind Regards

Neville

Oops, Dave already answered this!
> Each version of the index has an internal version number
> and there is an IndexReader#latest? method to determine
> if the version of the index that you are reading is 
> the current version. 
Silly me!
> -----Original Message-----
> From: Neville Burnell 
> Sent: Wednesday, 22 November 2006 3:43 PM
> To: ''ferret-talk at rubyforge.org''
> Subject: RE: [Ferret-talk] Help with Multiple Readers, 1 
> Writer scenario
> 
> Some time back in September, [sorry to be so slow], Dave wrote: 
> 
> > When you open an IndexReader on the index it is opened up on that 
> > particular version (or state) of the index. So any 
> operations on the 
> > IndexReader (like searches) will only show what was in the index at 
> > the time you opened it. Any modifications to the index (usually 
> > through and IndexWriter) that occur after you open the IndexReader 
> > will not appear in your searches.
> 
> > So to keep searches up to date you need to close and reopen your 
> > IndexReader every time you commit changes to the index.
> 
> Would it be possible to enhance IndexReader to report the 
> "version" of the index it is using, and to report if a newer 
> version of the index exists, eg perhaps #version and #current_version?
> 
> This would allow a long running IndexReader to detect that a 
> new index version is available, which is a problem if the 
> IndexWriter updates the index from another process. For 
> example, I am planning to divide my application into two 
> apps, one which services reader requests, and the other which 
> periodically updates the index if needed.
> 
> Kind Regards
> 
> Neville