[R] R for large data sets
Fan
xiao.gang.fan1 at libertysurf.fr
Thu Jan 17 22:03:03 CET 2002
AFAK, ROracle works only for R unix.
RODBC works very well for R Windows, I'd like to know
if there's any interests of ROracle for Windows users
(ex. large data sets, faster, etc.) ?
Thanks for advice
--
Xiao Gang FAN
Ernesto Jardim a écrit :
>
> Hi
>
> I'm using some large datasets and I found the ROracle package to be of
> great help.
>
> If you have the chance to create a database in Oracle or MySQL with one
> single table for your dataset, you can then use the ROracle package to
> access the dataset. I found several advantages on that.
>
> I don't import the data into my environment. I use a small function (see
> below) to access the dataset and because the result is a data.frame you
> can use it as usually.
>
> Your environment will not be to large and you'll have the ram memory
> less full.
>
> It's easier to select subsets with SQL than S/R language.
>
> Hope it helps
>
> Regards
>
> EJ
>
> --//--
>
> ora.fun <- function(){
>
> library(ROracle)
> m <- dbManager("Oracle")
> con <- dbConnect(m,user="user",password="password")
> dat <- quickSQL(con,"select ...")
> close(con)
> unload(m)
> dat
>
> }
>
> --//--
>
> On Tue, 2002-01-15 at 19:43, Prof Brian Ripley wrote:
> > On Tue, 15 Jan 2002, wei, xiaoyan wrote:
> >
> > > As a part of our regular data analysis, I have to read in large data sets
> > > with six columns and about a million rows. In Splus, this usually take a
> > > couple of minutes. I just tried R, it seems take forever to use read.table()
> > > to read in the data frame! It did not help much even though I specified
> > > colClasses and nrows in read.table().
> > >
> > > How is R's ability to analyze large data sets? I used R on solaris 2.6 and I
> > > used all default compilation flags when building the R package. Will it help
> > > if I use some compilation flags with higher optimization level?
> >
> > It will help to use R-patched, since I guess you are using 1.4.0.
> > Also, look in the list archives, as I answered this more fully earlier
> > today.
> >
> > In either S-PLUS or R, scan would be a better choice for such a dataset.
> >
> > --
> > Brian D. Ripley, ripley at stats.ox.ac.uk
> > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> > University of Oxford, Tel: +44 1865 272861 (self)
> > 1 South Parks Road, +44 1865 272860 (secr)
> > Oxford OX1 3TG, UK Fax: +44 1865 272595
> >
> > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
> > r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
> > Send "info", "help", or "[un]subscribe"
> > (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
> > _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
>
> -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
> r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
> Send "info", "help", or "[un]subscribe"
> (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
More information about the R-help
mailing list