If you never delete docs, then w/ the default merge policy, the docIDs
should never change.
But... this should be considered an impl detail of Lucene. In theory
someday this could change. EG there's an issue open (LUCENE-1076) to
allow a merge policy to select out-of-order merges, which they can
Right, but my question was whether merging segments will renumber docs *if
no documents are deleted*. Empirically, the answer is no. I've written
test code that indexes documents with a field equal to each document's
current id, and verified that the ids still match the field values even
after me
The doc id will get changed if the segments are merged. The doc id is
more depending on the order of documents being added.
Just think about it. The doc ids are starting from 0 to N. And when some
documents are deleted, they are marked deleted on .del file. So no
change there. When some docume
We do assign GUIDs to everything in the index for cases where longer-term
identity is necessary. For this case, using GUIDs would be prohibitively
expensive as we'd need to load the GUIDs for all search results. We might
have tens of thousands of results and only want to load a random 100, so
hav
Could you address your needs by assigning each document a unique
identifier (maybe you have a natural key, or maybe you could generate
a new GUID or something for each doc), and using those identifiers,
rather than internal Lucene docids, to track documents between the
search stage and the loading
Yes, I realize that storing document IDs persistently (for example) is a Bad
Idea. Partly I'm asking just to make sure I understand what's going on.
There is a use case, though. In some cases between when we do a search and
return some doc ids, and when we use those doc ids to load some documents
Why do you care? That is, what do you want to accomplish
that makes document ID renumbering relevant?
In general, it is unwise to rely on Lucene-assigned document
IDs. If you need an invariant document ID, assign it yourself.
If this is off base, could you supply your use-case?
Best
Erick
On Th
The FAQ clearly states that document IDs will not be re-assigned unless
something was deleted.
http://wiki.apache.org/lucene-java/LuceneFAQ#When_is_it_possible_for_document_IDs_to_change.3F
However, a number of other emails and posts I've read mention that
renumbering occurs when segments are merg
