Editing Apache Subversion (section)

===Repository types===
Subversion offers two types of repository storage.

====Berkeley DB (deprecated)====
The original development of Subversion used the [[Berkeley DB]] package.
Subversion has some limitations with Berkeley DB usage when a program that accesses the database crashes or terminates forcibly. No data loss or corruption occurs, but the repository remains offline while Berkeley DB replays the journal and cleans up any outstanding locks. The safest way to use Subversion with a Berkeley DB repository involves a single server-process running as one user (instead of through a shared filesystem).<ref name="backend">
{{cite book |author1=Ben Collins-Sussman |author2=Brian W. Fitzpatrick |author3=C. Michael Pilato |title= Version Control with Subversion: For Subversion 1.7 |year= 2011 |chapter= Chapter 5: Strategies for Repository Deployment |url= https://svnbook.red-bean.com/en/1.7/svn.reposadmin.planning.html#svn.reposadmin.basics.backends | publisher = O'Reilly}}
</ref> The Berkeley DB backend was deprecated in version 1.8.<ref>{{cite web |url=https://subversion.apache.org/docs/release-notes/1.8.html#bdb-deprecated |title=Apache Subversion 1.8 Release Notes |publisher=Apache Project |access-date=5 May 2020}}</ref>

====FSFS====
{{Redirect|FSFS|the Freesat service from Sky|Freesat from Sky|the book by Richard Stallman|Free Software, Free Society}}
In 2004, a new storage subsystem was developed and named FSFS.
It works faster than the Berkeley DB backend on directories with a large number of files and takes less disk space,
due to less logging.<ref name="backend"/>

Beginning with Subversion 1.2, FSFS became the default data store for new repositories.

The etymology of "FSFS" is based on Subversion's use of the term "filesystem" for its repository storage system.
FSFS stores its contents directly within the operating system's filesystem, rather than a structured system like Berkeley DB.
Thus, it is a "[Subversion] FileSystem atop the FileSystem".

====FSX====
A new filesystem, called FSX, is under development to remove some limitations of FSFS. As of Version 1.9, it was not considered production-ready.<ref>{{Cite web|url=https://subversion.apache.org/docs/release-notes/1.9.html#fsx|title = Apache Subversion 1.9 Release Notes}}</ref>