Why is a SVN dump of a single revision larger than a full dump?

Question

My repository is 2.5G. A dump via svnadmin dump myrepos > dumpfile is 5G. But when I do a dump like svnadmin dump myrepos -r 23785 > rev-23785.dumpfile where 23785 is the youngest revision the dump goes beyond 15G and at that point I stop the dump.

When requesting a dump for just the one revision, why is the result far larger than the entire dump?

Kaja

Answer 1

This page explains: http://linuxtopia.org/online_books/programming_tool_guides/version_control_with_subversion/svn.reposadmin.maint_8.html

"To ensure that the output of each execution of svnadmin dump is self-sufficient, the first dumped revision is by default a full representation of every directory, file, and property in that revision of the repository.

However, you can change this default behavior. If you add the --incremental option"

Mena

I see. A dump from 1st to the last can be efficient in storing the data between revisions. Just simply getting the lastest revision without any reference to the previous results in a full text dump for all actions that happen since the start. – Kaja