Thanks Mike. That was quite explanatory. A couple of doubts : 1. The deletions apply to buffered as well as stored-in-RAM documents. Right. So, if the index directory contains 1 document that matches a deleteDocument query, and 1 document in RAM that contains the same deleteDocument query, then, will the document-in-index-directory be deleted immediately, or when a flush is called. (It seems logical, that irrespective of the location of document, "actual" deletion occurs only when a flush is called .. just need to be doubly sure ...)
2. Yes I am planning to rewrite a project using Lucene 2.3.2. So, is the next version heading straight to 3.0 ??? (Sorry, if this question seems to be a little out of context of the current thread) Looking forward to a reply. Thanks Ajay Garg Michael McCandless-2 wrote: > > > java_is_everything wrote: > >> >> Hi all. >> >> This may seem a longish and informal mail, but do correct me if my >> assumptions are wrong anywhere, otherwise my actual doubt will make no >> sense. >> >> Say I opened an IndexWriter on an initially empty directory, using >> autocommit = true. Now, what I do is add and delete documents >> randomly. I >> set "x" as maxBufferedDocs and "y" as maxBufferedDeleteTerms (x < y). >> >> IndexWritrer starts its work. Now, I perfom the following sequences : >> >> STAGE 1 : >> Add "x-2" documents one after the another. Total docs >> in >> memory = x-2 (1) >> Delete 3 docs from memory >> Total docs >> in memory = x-5 (2) >> Add 5 docs one after another >> Total docs >> in memory = x (3) >> >> STAGE 2 : >> A flush happens, sice maxBufferedDocs reached. Total docs in >> memory = 0 (4) > > One correction here: the added doc count that triggers a flush does > *not* measure deletions. So, in your step (3) above, after having > added 2 of the 5 docs, IW will flush. Then it has 3 added docs > buffered in RAM. > >> Thus, it is also a commit. > > Assuming you're talking about trunk at this point (not 2.3), because > only trunk distinguishes commit() vs flush(): there's no guarantee > exactly when IW does a commit() when autoCommit is true. Also, > autoCommit is deprecated, meaning in 3.0 it will be hardwired to > false, so your application must commit() or close() when it's necessary. > >> STAGE 3 : >> Add x-10 docs one after other >> Total docs >> in memory = x-10 (5) > > Actually x-7 in memory now. > >> NOW ... I call deleteDocuments(Term term), which has potential >> matches at >> two places : >> a) x-15 (out of x-10) documents currently residing in memory. >> b) x-20 (out of x) documents currently in the index directory. >> (6) >> >> IndexWriter.close() is called >> (7) >> >> >> Now, my question is, will the index contain >> (i) a total of (x) + (x-10) - (x-15) documents >> (ii) a total of (x) + (x-10) - (x-20) documents >> (iii) a total of (x) + (x-10) - (x-15) - (x-20) documents > > Index will contain (iii), corrected to (x) + (x-7) - (x-15) - (x-20). > Ie the deletion always applies to any documents, flushed or buffered > in RAM. The deletion is fully independent of what buffering IW is > doing. > >> Secondly, will the answer change had I opened the IndexWriter in >> autocommit >> = false mode? > > No, you get the same result. autoCommit simply affects *when* the > changes become visible/durable to an external reader, not what changes > occur. Any series of changes using an IW will produce the same final > result regardless of autoCommit, assuming we're not talking about JRE/ > machine's crashing, etc. > >> Several other permutations of (autocommit mode), (points of flush >> call), >> (points of close call) exist, but I guess I will be fine if I get >> the answer >> to the first question itself. A little explanation will be highly >> obliged. > > autoCommit, points of flushing, points of committing, points of > merging, etc, should be fully independent of what changes (add/ > deletes) you are doing. > > Mike > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > -- View this message in context: http://www.nabble.com/Query-in-IndexWriter.deleteDocuments%28Term-term%29-tp18662995p18665652.html Sent from the Lucene - Java Users mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
