convert: Convert 'ddo' / 'ddf' Objects

In datadr: Divide and Recombine for Large, Complex Data

Description

Convert 'ddo' / 'ddf' objects between different storage backends

Usage

convert(from, to, overwrite = FALSE)

Arguments

from	a 'ddo' or 'ddf' object
to	a 'kvConnection' object (created with localDiskConn or hdfsConn) or NULL if an in-memory 'ddo' / 'ddf' is desired
overwrite	should the data in the location pointed to in to be overwritten?

Examples

d <- divide(iris, by = "Species")
# convert in-memory ddf to one stored on disk
dl <- convert(d, localDiskConn(tempfile(), autoYes = TRUE))
dl

Example output

* Saving connection attributes

Distributed data frame backed by 'kvLocalDisk' connection

 attribute      | value
----------------+----------------------------------------------------------------
 names          | Sepal.Length(num), Sepal.Width(num), Petal.Length(num), and 1 more
 nrow           | 150
 size (stored)  | 1.69 KB
 size (object)  | 11.48 KB
 # subsets      | 3

* Other attributes: getKeys()
* Missing attributes: splitSizeDistn, splitRowDistn, summary
* Conditioning variables: Species

datadr documentation built on May 1, 2019, 8:06 p.m.