dumpEnv: Dump Environment

Description

Dump an enviroment to a filehash database

Usage

dumpEnv(env, dbName)
dumpImage(dbName = "Rworkspace", type = NULL)
dumpObjects(
  ...,
  list = character(0),
  dbName,
  type = NULL,
  envir = parent.frame()
)
dumpDF(data, dbName = NULL, type = NULL)
dumpList(data, dbName = NULL, type = NULL)

Value

An object of class "filehash" is returned and a database is created.

Arguments

env: an environment
dbName: character, name of the filehash database
type: type of filehash database to create
...: R objects to be dumped to a filehash database
list,: character vector of object names to be dumped
envir: environment from which objects are dumped
data: a data frame

Functions

dumpImage(): Dump the Global Environment (analogous to save.image)
dumpObjects(): Dump named objects to a filehash database (analogous to save)
dumpDF(): Dump data frame columns to a filehash database
dumpList(): Dump elements of a list to a filehash database

Details

The dumpEnv function takes an environment and stores each element of the environment in a filehash database. Objects dumped to a database can later be loaded via dbLoad or can be accessed with dbFetch, dbList, etc. Alternatively, the with method can be used to evaluate code in the context of a database. If a database with name dbName already exists, objects will be inserted into the existing database (and values for already-existing keys will be overwritten).

dumpDF is different in that each variable in the data frame is stored as a separate object in the database. So each variable can be read from the database separately rather than having to load the entire data frame into memory. dumpList works in a simlar way.