kdesvn may use an internal log cache for some operations. Mostly it is used for the revision tree but when viewing simplified log in offline mode, too. The caches are organized as SQLite databases stored in
$HOME/.sqvnqt/logcache. Every numbered file is a storage for a different repository.
The databases may get large! So you may disable automatic update of log cache in settings.
You may simply remove a database, than no cached log will be given back for that repository (and no revision tree!) but when you do not disable automatic filling the cache on next open this repository or an associated working copy of it the cache will be refilled again.
kdesvn may work without network access, i.e. you can switch off the network access for kdesvn. This may be useful when working without network like on notebooks. In such cases kdesvn always gets the logs from the internal cache. This log is reduced to base functions due to technical reasons, so the cached log may (but not must) differ from real log. Differ means that it will not display all copy operations even Log follows node changes is set.