Andromeda-class: The Andromeda class

In Andromeda: Asynchronous Disk-Based Representation of Massive Data

The Andromeda class

Description

The Andromeda class is an S4 object.

This class provides the ability to work with data objects in R that are too large to fit in memory. Instead, these objects are stored on disk. This is slower than working from memory, but may be the only viable option.

Show the names of the tables in an Andromeda object.

Usage

## S4 method for signature 'Andromeda'
show(object)

## S4 method for signature 'Andromeda'
x$name

## S4 replacement method for signature 'Andromeda'
x$name <- value

## S4 replacement method for signature 'Andromeda'
x[[i]] <- value

## S4 method for signature 'Andromeda'
x[[i]]

## S4 method for signature 'Andromeda'
names(x)

## S4 method for signature 'Andromeda'
length(x)

## S4 method for signature 'Andromeda'
close(con, ...)

Arguments

object	An Andromeda object.
x	An Andromeda object.
name	The name of a table in the Andromeda object.
value	A data frame, Andromeda table, or other 'DBI' table.
i	The name of a table in the Andromeda object.
con	An Andromeda object.
...	Included for compatibility with generic close() method.

Value

A vector of names.

Tables

An Andromeda object has zero, one or more tables. The list of table names can be retrieved using the names() method. Tables can be accessed using the dollar sign syntax, e.g. andromeda$myTable, or double-square-bracket syntax, e.g. andromeda[["myTable"]]

Permanence

To mimic the behavior of in-memory objects, when working with data in Andromeda the data is stored in a temporary location on the disk. You can modify the data as you can see fit, and when needed can save the data to a permanent location. Later this data can be loaded to a temporary location again and be read and modified, while keeping the saved data as is.

Inheritance

The Andromeda inherits directly from SQLiteConnection. As such, it can be used as if it is a SQLiteConnection. RSQLite is an R wrapper around 'SQLite', a low-weight but very powerful single-user SQL database that can run from a single file on the local file system.

See Also

andromeda()

Examples

andr <- andromeda(cars = cars, iris = iris)

names(andr)
# [1] 'cars' 'iris'

close(andr)

Andromeda documentation built on Sept. 12, 2024, 7:41 a.m.