7 \title{Dump objects of database}
9 Dump R objects to a filehash database
12 dumpObjects(..., list = character(0), dbName, type = NULL, envir = parent.frame())
13 dumpImage(dbName = "Rworkspace", type = NULL)
14 dumpDF(data, dbName = NULL, type = NULL)
15 dumpList(data, dbName = NULL, type = NULL)
19 \item{\dots}{R objects to dump}
20 \item{list}{character vector of names of objects to dump}
21 \item{dbName}{character, name of database to which objects should be
23 \item{type}{type of database to create}
24 \item{envir}{environment from which to obtain objects}
25 \item{data}{a data frame or a list}
28 Objects dumped to a database can later be loaded via \code{dbLoad} or
29 can be accessed with \code{dbFetch}, \code{dbList}, etc.
30 Alternatively, the \code{with} method can be used to evaluate code in
31 the context of a database. If a database with name \code{dbName}
32 already exists, objects will be inserted into the existing database
33 (and values for already-existing keys will be overwritten).
35 \code{dumpDF} is different in that each variable in the data frame is
36 stored as a separate object in the database. So each variable can be
37 read from the database separately rather than having to load the
38 entire data frame into memory. \code{dumpList} works in a simlar
43 An object of class \code{"filehash"} is returned and a database is
47 \author{Roger D. Peng}
50 data <- data.frame(y = rnorm(100), x = rnorm(100), z = rnorm(100))
51 db <- dumpDF(data, dbName = "dataframe.dump")
52 fit <- with(db, lm(y ~ x + z))
55 db <- dumpList(list(a = 1, b = 2, c = 3), "list.dump")
58 \keyword{database}% at least one, from doc/KEYWORDS