Yes, "the most efficient possible" is associated with that JIRA, so only in 7x.
"Does this still hold if whole index is loaded into memory?" The decompression part yes, the disk seek part no. And it's also sensitive to whether the documentCache already has the document. I'd also make uniqueKey ant the _version_ fields docValues. Best, Erick On Tue, Nov 6, 2018 at 10:44 AM Wei <weiwan...@gmail.com> wrote: > > Thanks Yasufumi and Erick. > > ---. 2. "it depends". Solr will try to do the most efficient thing > possible. If _all_ the fields are docValues, it will return the stored > values from the docValues structure. > > I find this jira: https://issues.apache.org/jira/browse/SOLR-8344 Does > this mean "Solr will try to do the most efficient thing possible" only > working for 7.x? Is the behavior available for 6.6? > > -- This prevents a disk seek and decompress cycle. > > Does this still hold if whole index is loaded into memory? Also for the > benefit of performance improvement, does the uniqueKey field need to be > always docValues? Since it is used in the first phase of distributed > search. > > Thanks, > Wei > > > > On Tue, Nov 6, 2018 at 8:30 AM Erick Erickson <erickerick...@gmail.com> > wrote: > > > 2. "it depends". Solr will try to do the most efficient thing > > possible. If _all_ the fields are docValues, it will return the stored > > values from the docValues structure. This prevents a disk seek and > > decompress cycle. > > > > However, if even one field is docValues=false Solr will by default > > return the stored values. For the multiValued case, you can explicitly > > tell Solr to return the docValues field. > > > > Best, > > Erick > > On Tue, Nov 6, 2018 at 1:46 AM Yasufumi Mizoguchi > > <yasufumi0...@gmail.com> wrote: > > > > > > Hi, > > > > > > > 1. For schema version 1.6, useDocValuesAsStored=true is default, so > > there > > > > is no need to explicitly set it in schema.xml? > > > > > > Yes. > > > > > > > 2. With useDocValuesAsStored=true and the following definition, will > > Solr > > > > retrieve id from docValues instead of stored field? > > > > > > No. > > > AFAIK, if you define both docValues="true" and stored="true" in your > > > schema, > > > Solr tries to retrieve stored value. > > > (Except using streaming expressions or /export handler etc... > > > See: > > > > > https://lucene.apache.org/solr/guide/6_6/docvalues.html#DocValues-EnablingDocValues > > > ) > > > > > > Thanks, > > > Yasufumi > > > > > > > > > 2018年11月6日(火) 9:54 Wei <weiwan...@gmail.com>: > > > > > > > Hi, > > > > > > > > I have a few questions about using the useDocValuesAsStored option to > > > > retrieve field from docValues: > > > > > > > > 1. For schema version 1.6, useDocValuesAsStored=true is default, so > > there > > > > is no need to explicitly set it in schema.xml? > > > > > > > > 2. With useDocValuesAsStored=true and the following definition, will > > Solr > > > > retrieve id from docValues instead of stored field? if fl= id, title, > > > > score, both id and title are single value field: > > > > > > > > <field name="id" type="string" indexed="true" stored="true" > > > > docValues="true" required="true"/> > > > > > > > > <field name="title" type="string" indexed="true" stored="true" > > > > docValues="true" required="true"/> > > > > > > > > Do I need to have all fields stored="false" docValues="true" to make > > solr > > > > retrieve from docValues only? I am using Solr 6.6. > > > > > > > > Thanks, > > > > Wei > > > > > >
