[R] merging and working with BIG data sets. Is sqldf the best way??

Gabor Grothendieck ggrothendieck at gmail.com
Fri Oct 15 14:35:59 CEST 2010


On Fri, Oct 15, 2010 at 6:14 AM, Chris Howden
<chris at trickysolutions.com.au> wrote:
> Thanks for the advice Gabor,
>
> I was indeed not starting and finishing with sqldf(). Which was why it was
> not working for me. Please forgive a blatantly obvious mistake.
>
>
> I have tried what U suggested and unfortunately R is still having problems
> doing the join. The problem seems to be one of memory since I am receiving
> the below error message when I run the natural join using sqldf.
> Error: cannot allocate vector of size 250.0 Mb
> Timing stopped at: 32.8 0.48 34.79
>

Specify an external database so it uses an external, rather than "in
memory", database.  See example 6b (also shown in several other
examples) on the home page:

   sqldf(c("create...", "create...", "select..."), dbname = tempfile())

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Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com



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