Redshift for R
Provides a few functions to make it easier to access Amazon's Redshift service from R.
This library essentially does very little, other than provide some nicer functions that use the RJDBC package. The code includes by default the Postgresql 8.4-703 JDBC driver that is required for connecting to Amazon's Redshift service; installing this package would install all dependencies necessary to start querying and analysing. However, custom Postgresql drivers can be used (like later versions of the driver).
Installing
Installing with devtools is probably easiest or you can install from the source/tarball. The project is currently not part of CRAN.
Devtools
install.packages("devtools")
devtools::install_github("pingles/redshift-r")
Manually
Download the latest code tarball. Unzip the archive and run the following command in R:
install.packages("RJDBC", dependencies=T)
install.packages("/Users/me/Downloads/redshift-r-master", dependencies=F, repos=NULL, type="source")
Usage
require(redshift)
conn <- redshift.connect("jdbc:postgresql://blah.blah.eu-west-1.redshift.amazonaws.com:5439/data", "username", "password")
# conn is just a regular RJDBC connection object
# we can retrieve a list of tables
tables <- redshift.tables(conn)
# and get some info about the columns in one of those tables
cols <- redshift.columns(conn, "weblog")
# we can use RJDBC dbGetQuery to retrieve query results, perhaps from our weblog data
statuses_by_day <- dbGetQuery(conn, paste("SELECT DATE(timestamp) as dated, status, COUNT(1) as request_count",
"FROM weblog",
"GROUP BY DATE(time_stamp), status",
"ORDER BY dated"))
statuses_by_day$dated <- as.Date(statuses_by_day$dated)
statuses_by_day$status <- as.factor(statuses_by_day$status)
# finally, lets do a little scatter plot to see how this looks
require(ggplot2)
p <- ggplot(statuses_by_day, aes(x=dated, y=request_count))
p + geom_point(aes(color=status))
Checking package
Before committing changes to the project you can run the following command from the directory containing the cloned repo (i.e. ./redshift/..
)
$ R CMD check redshift
To Do
- Update R documentation with functions- generates warnings during check at the moment.
License
This R package includes the Postgresql JDBC binary which is distributed under the following license:
Copyright (c) 1997-2011, PostgreSQL Global Development Group
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. Neither the name of the PostgreSQL Global Development Group nor the names
of its contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
This Redshift R code is distributed under the Eclipse Public License.