[
https://issues.apache.org/jira/browse/LUCENE-7989?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Michael McCandless resolved LUCENE-7989.
----------------------------------------
Resolution: Won't Fix
> Add computed (at segment flush) doc values fields
> -------------------------------------------------
>
> Key: LUCENE-7989
> URL: https://issues.apache.org/jira/browse/LUCENE-7989
> Project: Lucene - Core
> Issue Type: Improvement
> Reporter: Michael McCandless
> Attachments: LUCENE-7989.patch
>
>
> This is a failed experiment but I thought I'd open an issue and post the
> patch in case it inspires others.
> It adds a new feature to Lucene, which lets you provide function (set via
> {{IndexWriterConfig}}) that is invoked at segment flush time to create a new
> doc values field as a function of all other doc values fields in that
> segment. The newly created field is "first class", i.e. behaves as if you
> had indexed actual doc values fields on your documents, it can participate in
> index sort, etc. The interesting thing about it is it has access to all
> other documents that made it into the flushed segment (by pulling doc values
> iterators for it).
> Anyway, I got the feature working, and it's surprisingly small core code
> change, but I had a very specific use case in mind, to "coalesce" documents
> by their families while sorting them by another field, and I realized that
> even though the feature is working, I cannot use it for this particular use
> case since the coalescing would break during merge (it's not just a simple
> "merge sort"). The test case I added, simulating my use case, fails on those
> seeds / test multipliers that trigger merging of the random index.
> I'll post a patch but I don't plan to push this any further!
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
