Skip to content
This repository has been archived by the owner on Dec 20, 2018. It is now read-only.

Latest commit

 

History

History
190 lines (128 loc) · 4.91 KB

README.md

File metadata and controls

190 lines (128 loc) · 4.91 KB
Raw

R Interface & SDK for the EXASOL Database

Copyright © EXASOL AG, Nuremberg (Germany). All rights reserved.
2004 - 2016

Build Status codecov.io

Installation

You need to have Rtools installed on Windows for R to be able to compile the package (for Linux see below). Plus, the R package devtools must be available in your workspace as it contains the install_github() method. The EXASOL package itself depends on the R package RODBC, which should be available on install from Github.

To install the EXASOL package:

require(devtools)
install_github("EXASOL/r-exasol")

Status

The low-level methods as regards exa.readData, exa.writeData and exa.createScript may work as expected, so should the DBI connection methods (dbConnect etc.; all tests passed). DBI querying methods also get close to being error-free: encoding and quoting should work properly, there could be errors about data type conversion. Writing tests have not yet been implemented (only quick-tests), but it hopefully happens in the near future.

Code coverage of tests:

codecov.io

EXASOL R Package

Description

The EXASOL R Package offers interface functionality such as connecting to, querying and writing into an EXASOL Database (version 5 onwards). It is optimised for massively parallel reading & writing from and to a multinode cluster. Implemented are DBI compliant methods for database access, querying and modiifcation. The package integrates with EXASOL's InDB R UDF capabilities, which allows to deploy and execute R code dynamically from an R application running on a client.

EXASOL is an InMemory RDBMS that runs in a MPP cluster (shared-nothing) environment. Leading the TPC-H benckmark, it is considered the fastest analytical data warehouse available. The community edition can be downloaded for free from the EXASOL Community Portal.

Prerequisites and Installation

  1. Install developer extensions for R to be able to build from sources

    For Windows: Install Rtools For Linux: Install the R-devel (RPM) or r-base-dev (Debian) package.

    The packages might change over time, so generally you can go to the official R-project website download section for your OS to find the package that are needed to build packages.

  2. Make sure you have ODBC and EXASOL ODBC installed and configured on your system. We recommend to create a DSN pointing to your database instance. Read the README of EXASOL's ODBC driver package for details.

    On Linux, you also need to install the development files for ODBC. Therefore please install unixodbc-devel (RPM) or unixodbc-dev (Debian) package.

Importing the package

To use the package import it as follows:

library(exasol)

Manual

The package comes with documentation accessible from R via the command ?exasol.

Package index

DBI: Driver-related

EXADriver-class : An interface driver object to the EXASOL Database.

dbDriver : Load database drivers.

dbUnloadDriver : Unload a driver.

dbConnect : Creates a connection to an EXASOL Database.

dbListConnections : List currently open connections.

DBI: Connection-related

EXAConnection-class : An object holding a connection to an EXASOL Database.

dbDisconnect : Disconnects the connection.

dbSendQuery : Sends an SQL statment to an EXASOL DB, prepares for result fetching.

dbGetQuery : Executes the query, fetches and returns the entire result set.

dbGetException : TODO

dbListResults : TODO

dbListFields : TODO

dbListTables : TODO

dbReadTable : Reads a DB table.

dbWriteTable : Writes a data.frame into a table. If the table does not exist, it is created.

dbExistsTable : Checks if a table exists in an EXASOL DB.

dbRemoveTable : Removes a table.

dbBegin : Starts a DB transaction.

dbEnd : Ends a DB transaction.

dbCommit : Sends a commit.

dbRollback : Rolls the current DB transaction back.

DBI: Result set-related

EXAResult-class : An object that is associated with a result set in an EXASOL Database.

dbFetch : Fetches a subset of an result set.

dbClearResult : Frees all resources associated with an EXAResult.

dbColumnInfo : TODO

dbGetStatement : TODO

dbHasCompleted : TODO

dbGetRowsAffected : TODO

dbGetRowCount : TODO

Low-level methods

exa.readData : Execute a SQL query on an EXASolution database and read results fast.

exa.writeData : Write a data.frame into an EXASOL table fast.

exa.createScript : Deploys an R function as an UDF in the EXASolution database.

EXAupper : Changes an identifier into uppercase, except for it is quoted.

dbCurrentSchema : Fetches and outputs the current schema from an EXASOL DB.