About reading and writing to files

Rich Morin rdm at cfcl.com
Fri May 30 01:30:50 PDT 2003

At 3:04 AM -0500 5/30/03, Bingrui Foo wrote:
>I'm wondering in freeBSD, if I have a directory with 10,000 files, or
>maybe even 100,000 files, each about 5 kb long. Wondering will reading and
>writing to any one of these files in C be affected by the sheer number of
>these files? Will the access time be affected significantly?
>Just wondering because not sure whether I should put these data in a
>database or just use files with unique names.
>Also will separating the files into many directories help?

Looking up .../x/12/34/56 can be done in logarithmic time (i.e., look up
.../x/12, then .../x/12/34, then .../x/12/34/56); looking up 
.../y/123456 (unless some optimization has been added) will require a 
linear scan
through the directory.  In short, don't go there...

email: rdm at cfcl.com; phone: +1 650-873-7841
http://www.cfcl.com/rdm    - my home page, resume, etc.
http://www.cfcl.com/Meta   - The FreeBSD Browser, Meta Project, etc.
http://www.ptf.com/dossier - Prime Time Freeware's DOSSIER series
http://www.ptf.com/tdc     - Prime Time Freeware's Darwin Collection

More information about the freebsd-questions mailing list