You're probably right, that it's only new and merged segments that will be of the new format. Solr 4.3 will be able to search the old segments.
-- Jan Høydahl, search solution architect Cominvent AS - www.cominvent.com 10. mai 2013 kl. 15:27 skrev Shawn Heisey <s...@elyograg.org>: > On 5/10/2013 5:11 AM, Jan Høydahl wrote: >> Hi, >> >> The fastest way to upgrade is to leave luceneMatchVersion as LUCENE_40. Then >> you will not get any surprises wrt changed behavior for existing >> functionality. but you will get all the bug fixes. You can test it out on >> your dev box. > > I've wondered if it would be possible to create a list on the wiki of > how Solr behaves differently with each successive bump in > luceneMatchVersion. That would be very helpful in helping people with > their upgrades. > >> The first time Solr reads the existing index, it will be converted to 4.3 >> format, so keep a backup in case you wish to downgrade again, since 4.0 will >> not read this index. I'm not 100% sure if this auto conversion will >> compressed stored fields for you or if you need a re-index for that. > > I'm not sure this is right. Solr should leave existing segments alone, > but write new segments in the new format. An optimize would be required > to upgrade the format of the whole index. Of course a full reindex > after changing luceneMatchVersion is the recommended way to go, because > that version number change might result in the indexing happening > differently. > > One person on IRC had trouble with the compression in 4.2.1 not being > enabled even when deleting the entire index directory and starting over, > but the entire situation sounded like their upgrade was perhaps not > complete, and I never could figure out what was happening. > > Thanks, > Shawn >