On Fri, Oct 21, 2016 at 08:03:53PM +0200, Tinu Weber wrote: > On Fri, Oct 21, 2016 at 17:20:53 +0000, Alive 4ever wrote: > > [...] It seems that the local pacman databases are just subdirectories > > with text files (desc, files) and gzipped text (mtree). > > No wonder why local pacman databases tend to slow down over time and > > need to be optimized periodically. > This is a little contradictory: if it is just directories with text > files (plain or compressed), how does it need "periodical optimisation"? > What is optimised? And how? Local text files uses the underlying filesystem capability to optimize. Currently, pacman package includes a ``pacman-optimize`` script to do manual periodic local database optimization. Invoking ``pacman-optimize --help`` should give you a hint that pacman developers recognize that there is a problem with many small files: filesystem fragmentation. Basically, the optimization is just file system rotation. The old databases are archived into tar files in the tmp, the local database is moved/renamed, the tar archive of local database is extracted back to its original location. If everything goes fine, the renamed old database is deleted. > > > This would provide faster access for local database as sql databases > > are optimized for fast access. > This just adds complexity, and for what? Marginal performance gain (if > at all? honestly, `pacman -Q` runs almost instantly here). Filesystem fragmentation is no problem for faster disk. > > Best, > Tinu/ayekat
