Change SVN_FS_BASE__MIN_FORWARD_DELTAS_FORMAT to be larger than SVN_FS_BASE__FORMAT_NUMBER.
Whether repositories created by an svn patched in this way will be interoperable with repositories created by an unpatched svn is LAAEFTR'd. I'd be cautious and change db/fs-type or db/format. Vyacheslav Zholudev wrote on Fri, Nov 25, 2011 at 12:04:22 +0100: > Hi Daniel, > > would it be easy to change the code (I want to do it for my experiments) so > that the HEAD (youngest) revisions are stored as fulltexts? Or is it > something that was not foreseen by design to easily switch between approaches > of representing history information? > > Thanks, > Vyacheslav > > On Nov 25, 2011, at 11:59 AM, Daniel Shahaf wrote: > > > Vyacheslav Zholudev wrote on Fri, Nov 25, 2011 at 11:13:00 +0100: > >> > >>> Old BDB-backed repositories stored the older revision as fulltext and > >>> newer revisions as deltas. > >> > >> Really? > > > > It seems that I should have swapped "older" and "newer" in the quoted > > sentence. Thanks for catching that. > > > >> Here is a quotation from SVN 1.4.6 libsvn_fs_base/note/structure: > >> "At present, Subversion generally stores > >> the youngest strings in "fulltext" form, and older strings as "delta"s > >> against them (unless the delta would save no space compared to the > >> fulltext). > >> " > >> My own experiments with SVN 1.4 code confirm that. > >> > >> > >> > >>> Repositories created with or 'svnadmin > >>> upgrade'd by 1.6 and newer reverse this for new revisions of files > >>> (while making sure not to introduce a dependency loop in the direction > >>> of deltas). > >>> > >>> http://subversion.apache.org/docs/release-notes/1.6#bdb-forward-deltas > >>> > >>> On Friday, November 25, 2011 1:08 AM, "Vyacheslav Zholudev" > >>> <vyacheslav.zholu...@gmail.com> wrote: > >>>> Hi, > >>>> > >>>> how does SVN 1.7.1 store fulltext and deltas in the BDB backend? From > >>>> some time ago I remember that previous versions of SVN stored "almost" > >>>> always a HEAD revision as fulltext, and others as reverse deltas.(except > >>>> the case when a delta is bigger that fulltext) Was this behavior changed > >>>> in SVN 1.7? I've looked at the notes about BDB and they don't differ > >>>> almost at all from SVN 1.4's ones. Of course, I could look into the code > >>>> more carefully, but my hope was that it wouldn't be a big deal to give > >>>> me a short answer, if possible. > >>>> > >>>> Thanks in advance! > >>>> > >>>> Best, > >>>> Vyacheslav > >>>> > >>>> > >>>> > >> >
