> On Nov 28, 2016, at 9:38 AM, Shawn Heisey <apa...@elyograg.org> wrote: > > […] Typically > a merge or optimize will only require double the space, but there are > certain worst-case scenarios where it can require triple. I do not know > what causes the worst-case situation.
Worst case: 1. Disable merging. 2. Delete all the documents. 3. Add all the documents. 4. Enable merging. After step 3, you have two copies of everything, one deleted copy and one new copy. The merge makes a third copy. This can happen with any search engine that uses the same kind of segment management as Lucene. We learned about this with Ultraseek, back in the mid-1990’s. wunder Walter Underwood wun...@wunderwood.org http://observer.wunderwood.org/ (my blog)