Problem

I dumped out my repository using svnadmin dump and the dumpfile it produced is much larger than the original Subversion repository. What is going on?

Solution

The svnadmin dump command produces a plain ASCI text version of a Subversion repository database. Being a plain text file it cannot take advantage of compression used when storing data in the Subversion repository database, hence the size increase.

Discussion

The dumpfile format is both human readable (if you are so inclined) and platform independent. This makes it idea for moving repositories around between different operating environments.

The dumpfile is also a linear representation of all revisions held in the Subversion virtual file system. Consequently it lends itself to filtering using svndumpfilter. This allows administrators to remove parts of repositories, or to isolate parts of repositories so that they can be loaded into other repositories. (Covered in detail in Subversion Guru training.)