Shalin, that makes sense. But it also seems like the details of _version_ can and should be handled internally and not be subjected to the vagaries of deployment. Put another way, whenever _version_ is used, shouldn't its storage should be determined by the code, not schema.xml?
SOLR-5944 is a super important issue with endless applications. Pricing is a huge use case: price field values fluctuate by the minute, hour, day, etc., but docs remain otherwise very stable. But there are many other cases with similar semantics (e.g. share counts, purchase order quantities, assigned resources). So, I guess I'm encouraging you to do whatever it takes to _version_ to make SOLR-5944 work. :-) P.S. Many thanks to Chris Hostetter for his corrections and clarifications. I'm learning a lot from this thread. -----Original Message----- From: Shalin Shekhar Mangar [mailto:[email protected]] Sent: Thursday, June 25, 2015 12:48 AM To: [email protected] Subject: Re: Version field as DV On Tue, Jun 23, 2015 at 6:41 PM, Adrien Grand <[email protected]> wrote: > For the record, there is an experimental postings format in > lucene/sandbox called IDVersionPostingsFormat that stores both the ID > and version in a postings format. This way you don't have to perform > additional seeks to look up the version, and it's even optimized for > id look ups with a minimum version for faster optimistic concurrency. Yeah, I have looked at it in the past but in the context of updateable DocValues, I feel that there is no way to support updateable doc values if we use the IDVersionPostingsFormat. This is because we must update a DocValue field together with the version field atomically or else we run into consistency issues. > > On Mon, Jun 22, 2015 at 4:41 PM, Ishan Chattopadhyaya > <[email protected]> wrote: >> Hi all, >> I am looking to try out _version_ as a docvalue (SOLR-6337) as a >> precursor to SOLR-5944. Towards that, I want the _version_ field to >> be stored=indexed=false, docValues=true. >> >> Does someone know about the performance implications of retrieving >> the _version_ as a docvalue, e.g. accessing docvalue vs. a stored >> field? Is there any known inefficiency when using a docvalue (as >> opposed to a stored >> field) due to random disk seeks, for example? >> Regards, >> Ishan > > > > -- > Adrien ************************************************************************* This e-mail may contain confidential or privileged information. If you are not the intended recipient, please notify the sender immediately and then delete it. TIAA-CREF *************************************************************************
