[R] SQL Primer for R

Ajay ohri ohri2007 at gmail.com
Mon Aug 25 16:38:03 CEST 2008


Not really, if you want R to be as mainstream as other stats packages
that can read more than a few gigabytes on the PC.

R's relative inefficiency in reading large datasets (due to the RAm
loading thing) ,forces people to opt for lesser softwares which are
way too expensive for annual license fees or opt for more expensive
RAM.

This problem gets even more accelerated in price conscious developing
countries like mine thus creating a new digital divide.

Ajay

On Mon, Aug 25, 2008 at 7:09 PM, Gabor Grothendieck
<ggrothendieck at gmail.com> wrote:
> This would be a function of the database software more than R.  For sqlite
> a few dozen gigabytes should be ok.  Other databases can handle even
> larger requirements.
>
> On Mon, Aug 25, 2008 at 9:17 AM, Ajay ohri <ohri2007 at gmail.com> wrote:
>> R 's ability to work with large data sets is limited on PC. I am
>> trying it on cloud to overcome this but need help from other
>> programmers.
>>
>> Also tutorials would help to newbies
>>
>> regards,
>>
>> Ajay
>>
>> On Mon, Aug 25, 2008 at 6:42 PM, ivo welch <ivowel at gmail.com> wrote:
>>> Dear R wizards:
>>>
>>> I decided to take the advice in the R data import/export manual and
>>> want to learn how to work with SQL for large data sets.  I am trying
>>> SQLite with the DBI and RSQLite database interfaces.  Speed is nice.
>>> Alas, I am struggling to find a tutorial that is geared for the kind
>>> of standard operations that I would want in R.  Simple things:
>>>
>>> *  how to determine the number of rows in a table.  (Of course, I
>>> could select a row of data and then use this.)
>>>
>>> *  how to insert a new column into my existing SQL table---say, the
>>> rank of another variable---and save it back.  Am I supposed to create
>>> a new data frame, then save it as a new table, then delete the old SQL
>>> table?
>>>
>>> *  how to save a revised version of my table in a different sort order
>>>  (with or without deleting the original table).  <-- I guess this is
>>> not appropriate, as I should think of SQL tables as unordered.
>>>
>>> I guess these would make nice little text snippets in the R Data
>>> import/export manual, too.  help appreciated.
>>>
>>> regards,
>>>
>>> /ivo
>>>
>>> ______________________________________________
>>> R-help at 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.
>>>
>>
>>
>>
>> --
>> Regards,
>>
>> Ajay Ohri
>> http://tinyurl.com/liajayohri
>>
>> ______________________________________________
>> R-help at 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.
>>
>



-- 
Regards,

Ajay Ohri
http://tinyurl.com/liajayohri



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