簡睿隨筆 《科技篇》

Sensitivity to interruptions

very; crashes and permission problems can leave the database “wedged”, requiring journaled recovery procedures.

quite insensitive.

Usable from a read-only mount

no

yes

Platform-independent storage

no

yes

Usable over network filesystems

no

yes

Repository size

slightly larger

slightly smaller

Scalability: number of revision trees

database; no problems

some older native filesystems don't scale well with thousands of entries in a single directory.

Scalability: directories with many files

slower

faster

Speed: checking out latest code

faster

slower

Speed: large commits

slower, but work is spread throughout commit

faster, but finalization delay may cause client timeouts

Group permissions handling

sensitive to user umask problems; best if accessed by only one user.

works around umask problems

Code maturity

in use since 2001

in use since 2004