On 03/01/2023 03.54, Shawn Heisey wrote:
Some features like grouping appear to require docValues to work at all.
If some shards have docValues and some don't, those features are likely
to break horribly, or at least not return expected results.
You're probably right in saying that this will break horribly in the
general case. For our case, it's pretty safe, as the docValues schema
change was only made on the unique key field, which we never use for
grouping/faceting/etc.
I fear that this
patch would result in incorrect results being returned without an error
for features that use docValues, like grouping, sorting, facets, etc.
I think you're right, and it's probably not wise to merge this into
Solr. We submitted the patch with the idea that it might help people who
faced similar issues, but a couple of flashy warning signs would have
been a good idea.
Thanks for the feedback!
For a bit more context: we noticed that without docValues, the unique
key field ends up wasting gigabytes of memory per core (in field cache,
iirc). One entry per unique identifier. Regardless of whether or not the
core is even being hit. With docValues enabled, this is ameliorated.
This was pretty painful in large cloud instances with many large shards
in memory constrained environments.
- Bram
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org
For additional commands, e-mail: dev-h...@solr.apache.org
