On Mon, Dec 3, 2012 at 4:39 PM, Hyrum K Wright <hy...@hyrumwright.org> wrote: > > On Mon, Dec 3, 2012 at 7:08 AM, Philip Martin <philip.mar...@wandisco.com> > wrote: >> >> Prompted by a question on users I wondered how SQLite's vacuum >> (http://sqlite.org/lang_vacuum.html) would affect wc.db size. On a >> Subversion trunk working copy I have been using for months the size was >> reduced from 2.3MB to 1.3MB which isn't really a significant change. >> >> For a further test I checked-out a ^/subversion/branches working copy >> for a wc.db of 93MB with 121738 rows, I made it sparse with 66046 rows >> and it was still 93MB, then I ran vacuum and it was reduced to 51MB. I >> have a gcc working copy with some subtrees switched to an empty >> directory. There vacuum reduced wc.db from 47MB to 8.1MB. >> So it appears that vacuum is interesting if the number of rows decreases >> dramatically. >> >> SQLite has auto_vacuum but it comes with a warning that it may make >> fragmentation worse (http://sqlite.org/pragma.html#pragma_auto_vacuum) >> so it's not clear whether we should enable it. Perhaps we should add a >> "vacuum" to cleanup? A full vacuum rewrites all the tables so it's not >> a trivial operation but it is reasonably fast for the working copies on >> local disk that I tried. > > > I think adding "vacuum" to cleanup is a reasonable first step. "cleanup" is > an explicit operation that a user could reasonably expect to take some > non-trivial amount of time. We already remove unneeded pristines during > cleanup, might as well do the same thing with wc.db space. > +1.
-- Ivan Zhakov
