I noticed that Ubuntu pushed java 6 update 14 as an update to 9.04 today. This update includes compressed object pointers which are designed to reduce memory requirements with 64bit JVMs.
Has anyone experimented with this to see if it provides any benefit to Solr? If not, can anyone comment on whether they would expect it provide a significant benefit? I don't know enough about how the internal caches are structured to say anything. Our servers are running on 8.04 LTS, so upgrading would be a bit of a chore. I'm hoping that someone can say "it's not worth it" before we try it ourselves.
