I'm encountering excruciatingly slow load times for character vectors in
R 2.6.0-- up to 30sec for a 15K file that contains a no-attributes
character vector of length ~1e4 and object size ~0.5MB. In R 2.5.1,
repeated loads of the same set of files are near-instantaneous.
The problem is proving tricky to reproduce consistently from scratch, so
I have attached the 3 files used in the examples below. If I create a
similar-looking object from scratch, then save it and re-load it a few
times, the problem doesn't always occur... at least not in that session.
FWIW I have noticed that the time taken to load seems to be roughly a
power of 2 of the "base slow load time"-- could be a red herring.
The problem seems specific to character vectors-- I noticed it with
entire workspaces and have whittled it down to char vecs only.
The example below is from a brand-new session with only the basic
packages loaded; delays in my real sessions are much longer.
Mark Bravington
CSIRO Mathematical & Information Sciences
Marine Laboratory
Castray Esplanade
Hobart 7001
TAS
ph (+61) 3 6232 5118
fax (+61) 3 6232 5012
mob (+61) 438 315 623
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.
> system.time( load( 'd:/r2.0/t1.rda'))
user system elapsed
0.5 0.0 0.5
> system.time( load( 'd:/r2.0/t1.rda')) # same file; slower
user system elapsed
3.5 0.0 3.5
> system.time( load( 'd:/r2.0/t1.rda'))
user system elapsed
4.13 0.00 4.13
> system.time( load( 'd:/r2.0/t1.rda'))
user system elapsed
3.51 0.00 3.52
> system.time( load( 'd:/r2.0/t2.rda')) # different bigger file
user system elapsed
4.42 0.00 4.42
> system.time( load( 'd:/r2.0/t2.rda')) # same file; slower
user system elapsed
10.44 0.00 10.44
> system.time( load( 'd:/r2.0/t2.rda'))
user system elapsed
10.79 0.00 10.80
> system.time( load( 'd:/r2.0/t2.rda'))
user system elapsed
10.39 0.00 10.41
> system.time( load( 'd:/r2.0/t1.rda')) # the smaller file again; slower
user system elapsed
10.67 0.00 10.69
> system.time( load( 'd:/r2.0/t3.rda')) # different smaller file
user system elapsed
10.51 0.00 10.52
> system.time( load( 'd:/r2.0/t2.rda')) # now bigger file again: slower
user system elapsed
14.61 0.00 14.61
--please do not edit the information below--
Version:
platform = i386-pc-mingw32
arch = i386
os = mingw32
system = i386, mingw32
status =
major = 2
minor = 6.0
year = 2007
month = 10
day = 03
svn rev = 43063
language = R
version.string = R version 2.6.0 (2007-10-03)
Windows XP (build 2600) Service Pack 2.0
Locale:
LC_COLLATE=English_Australia.1252;LC_CTYPE=English_Australia.1252;LC_MON
ETARY=English_Australia.1252;LC_NUMERIC=C;LC_TIME=English_Australia.1252
Search Path:
Search Path:
.GlobalEnv, package:stats, package:graphics, package:grDevices,
package:utils, package:datasets, package:methods, Autoloads,
package:base
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