Hi, > Unless you specify an in-memory database the database is stored on disk.
Thanks for your explanation. I just downloaded 'sqldf'. Where can I find the option for that? In sqldf I can't see the command. I looked at: envir = parent.frame() doesn't appear to be the one. - Gundala Viswanath Jakarta - Indonesia > > On Fri, Jan 16, 2009 at 10:59 AM, Gundala Viswanath <gunda...@gmail.com> > wrote: >> Hi Gabor, >> >>> the file itself is read into a database >> >> The above doesn't use RAM memory? >> >> Rgds, >> GV. >> >>> without ever going through R so your memory requirements correspond to what >>> you extract, not the size of the file. >>> >>> On Fri, Jan 16, 2009 at 10:49 AM, Gundala Viswanath <gunda...@gmail.com> >>> wrote: >>>> Hi Gabor, >>>> >>>> Do you mean storing data in "sqldf', doesn't take memory? >>>> For example, I have 3GB data file. with standard R object using >>>> read.table() >>>> the object size will explode twice ~6GB. My current 4GB RAM >>>> cannot handle that. >>>> >>>> Do you mean with "sqldf", this is not the issue? >>>> Why is that? >>>> >>>> Sorry for my naive question. >>>> >>>> - Gundala Viswanath >>>> Jakarta - Indonesia >>>> >>>> >>>> >>>> On Fri, Jan 16, 2009 at 9:09 PM, Gabor Grothendieck >>>> <ggrothendi...@gmail.com> wrote: >>>>> On Fri, Jan 16, 2009 at 5:52 AM, r...@quantide.com <r...@quantide.com> >>>>> wrote: >>>>>> I agree on the database solution. >>>>>> Database are the rigth tool to solve this kind of problem. >>>>>> Only consider the start up cost of setting up the database. This could >>>>>> be a >>>>>> very time consuming task if someone is not familiar with database >>>>>> technology. >>>>> >>>>> Using sqldf as mentioned previously on this thread allows one to use >>>>> the SQLite database with no setup at all. sqldf automatically creates >>>>> the database, generates the record layout, loads the file (not going >>>>> through >>>>> R but outside of R so R does not slow it down) and extracts the >>>>> portion you want into R issuing the appropriate calls to RSQLite/DBI and >>>>> destroying the database afterwards all automatically. When you >>>>> install sqldf it automatically installs RSQLite and the SQLite database >>>>> itself so the entire installation is just one line: >>>>> install.packages("sqldf") >>>>> >>>>> ______________________________________________ >>>>> R-help@r-project.org mailing list >>>>> https://stat.ethz.ch/mailman/listinfo/r-help >>>>> PLEASE do read the posting guide >>>>> http://www.R-project.org/posting-guide.html >>>>> and provide commented, minimal, self-contained, reproducible code. >>>>> >>>> >>> >> > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.