[
https://issues.apache.org/jira/browse/SOLR-8220?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15011760#comment-15011760
]
Keith Laban commented on SOLR-8220:
-----------------------------------
bq. I used that to ensure we're not re-adding unstored docvalues a second time
to the same document. This is necessary here so that we don't re-add such
fields to a document was obtained from the documentCache and already has all
unstored docvalues in it. I can create a set of fields inside the
StoredDocument class so that a hasField lookup can be speeded up. However,
given that it is a Lucene class, I have left this be. Any suggestions?
This shouldn't be an issue since the hook is called after caching is done. This
could get really expensive if you are getting a few thousand documents that
have hundreds of fields. I think the real issue is how do we cache this
efficiently. I think that will require modifying LazyDocument, (see my comments
above)
bq. If it is a dynamic field, it will still work; a wrong field name won't work
here. Shouldn't a wrong field name throw an exception, rather than silently
dropping it? I am split either ways.
This is more a backwards compat thing. What is current behavior for stored
fields?
bq. I think this creates at most only the value source object, which isn't too
bad. Internally, it uses the docvalues API.
for a string field, getValueSource creates a new StrFieldSource and getValues
creates a new DocTermsIndexDocValues. Both of these closures add overhead
especially if you're doing this hundreds of times for thousands of documents
> Read field from docValues for non stored fields
> -----------------------------------------------
>
> Key: SOLR-8220
> URL: https://issues.apache.org/jira/browse/SOLR-8220
> Project: Solr
> Issue Type: Improvement
> Reporter: Keith Laban
> Attachments: SOLR-8220-ishan.patch, SOLR-8220-ishan.patch,
> SOLR-8220.patch, SOLR-8220.patch
>
>
> Many times a value will be both stored="true" and docValues="true" which
> requires redundant data to be stored on disk. Since reading from docValues is
> both efficient and a common practice (facets, analytics, streaming, etc),
> reading values from docValues when a stored version of the field does not
> exist would be a valuable disk usage optimization.
> The only caveat with this that I can see would be for multiValued fields as
> they would always be returned sorted in the docValues approach. I believe
> this is a fair compromise.
> I've done a rough implementation for this as a field transform, but I think
> it should live closer to where stored fields are loaded in the
> SolrIndexSearcher.
> Two open questions/observations:
> 1) There doesn't seem to be a standard way to read values for docValues,
> facets, analytics, streaming, etc, all seem to be doing their own ways,
> perhaps some of this logic should be centralized.
> 2) What will the API behavior be? (Below is my proposed implementation)
> Parameters for fl:
> - fl="docValueField"
> -- return field from docValue if the field is not stored and in docValues,
> if the field is stored return it from stored fields
> - fl="*"
> -- return only stored fields
> - fl="+"
> -- return stored fields and docValue fields
> 2a - would be easiest implementation and might be sufficient for a first
> pass. 2b - is current behavior
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
