X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/agedu/blobdiff_plain/09fd761910218169867abf96b15d3cc1bc36e379..522edd92f2bbef89ccd1dd0a3e874516fb47e2ef:/agedu.but diff --git a/agedu.but b/agedu.but index ff97346..f4fdb1d 100644 --- a/agedu.but +++ b/agedu.but @@ -572,11 +572,13 @@ efficiently perform the queries it needs; this data structure requires \cw{O(N log N)} storage. This is larger than you might expect; a scan of my own home directory, containing half a million files and directories and about 20Gb of data, produced an index file -nearly a third of a Gb in size. Furthermore, since the data file -must be memory-mapped during most processing, it can never grow -larger than available address space, which means that any use of -\cw{agedu} on a file system more than about ten times the above size -is probably going to have to be done on a 64-bit computer. +over 60Mb in size. Furthermore, since the data file must be +memory-mapped during most processing, it can never grow larger than +available address space, so a \em{really} big filesystem may need to +be indexed on a 64-bit computer. (This is one reason for the +existence of the \cw{-D} and \cw{-L} options: you can do the +scanning on the machine with access to the filesystem, and the +indexing on a machine big enough to handle it.) The data structure also does not usefully permit access control within the data file, so it would be difficult \dash even given the