[R] Basic Question about Rsql and

[Lorenzo Isella]

Dear All,
I know rather little about the sql family of databases, but from time to  
time I have to access some data which is stored e.g. in a mysql database.
I came across these posts

http://bit.ly/WGyGTW
http://bit.ly/VR4ZkN
http://bit.ly/VR51t0

I am now surprised about the amount of data one can handle in R on a  
standard pc with some Gb of RAM.
Please see the code at the end of the email.
I read and entire database into x.
x feels like a dataframe, but the is.data.frame(x) tells me that it is not.
Knowing little about sql, can I in any case forget all the technicalities  
and treat x as if it was a data frame to carry out my analysis in R? Or is  
a word of caution in order?
Many thanks

Lorenzo


################################################################################

library(RMySQL)
require(ETLUtils)

login <- list()
login$user <- "genome"
login$host <- "genome-mysql.cse.ucsc.edu"


x <- read.dbi.ffdf(
query = "select * from mm9.knownGene",
dbConnect.args = list(drv = dbDriver("MySQL"),
   user = login$user, host = login$host),
VERBOSE=TRUE)