We currently use Clearcase for a large number of large projects. We use SQL Server as the file store in the background, and it has eventually reached a point where accessing files is just too slow.
Looking at GIT and Mercurial, we see a distributed VCS based on storing file differences - which has the potential to get much better local performance.
Does anybody know whether Jazz RTC has a file store backed by file differences or by a database? (The rumour mill is suggesting it is backed by DB2 :/ )
I suppose you mean Jazz RTC, which has a version control included.
Its Jazz RTC server supports DB2, Sql Server and Oracle.
However, a Jazz platform is very different from a DVCS like Git and Mercurial: it is an application Hub made to facilitate the communication between several software about the development lifecycle (requirements, versionning, changes, builds, ...).
The version control part is only a small portion of Jazz.