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From John Davis <johndavis925...@gmail.com>
Subject Re: Enabling/disabling docValues
Date Mon, 10 Jun 2019 01:53:48 GMT
Understood, however code is rarely random/undefined. Does lucene look at %
docs in each state, or the first doc or something else?

On Sun, Jun 9, 2019 at 1:58 PM Erick Erickson <erickerickson@gmail.com>
wrote:

> It’s basically undefined. When segments are merged that have dissimilar
> definitions like this what can Lucene do? Consider:
>
> Faceting on a text (not sortable) means that each individual token in the
> index is uninverted on the Java heap and the facets are computed for each
> individual term.
>
> Faceting on a SortableText field just has a single term per document, and
> that in the docValues structures as opposed to the inverted index.
>
> Now you change the value and start indexing. At some point a segment
> containing no docValues is merged with a segment containing docValues for
> the field. The resulting mixed segment is in this state. If you facet on
> the field, should the docs without docValues have each individual term
> counted? Or just the SortableText values in the docValues structure?
> Neither one is right.
>
> Also remember that Lucene has no notion of schema. That’s entirely imposed
> on Lucene by Solr carefully constructing low-level analysis chains.
>
> So I’d _strongly_ recommend you re-index your corpus to a new collection
> with the current definition, then perhaps use CREATEALIAS to seamlessly
> switch.
>
> Best,
> Erick
>
> > On Jun 9, 2019, at 12:50 PM, John Davis <johndavis925254@gmail.com>
> wrote:
> >
> > Hi there,
> > We recently changed a field from TextField + no docValues to
> > SortableTextField which has docValues enabled by default. Once I did
> this I
> > do not see any facet values for the field. I know that once all the docs
> > are re-indexed facets should work again, however can someone clarify the
> > current logic of lucene/solr how facets will be computed when schema is
> > changed from no docValues to docValues and vice-versa?
> >
> > 1. Until ALL the docs are re-indexed, no facets will be returned?
> > 2. Once certain fraction of docs are re-indexed, those facets will be
> > returned?
> > 3. Something else?
> >
> >
> > Varun
>
>

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