stow: Object storage
In rpg: Easy Interface to Advanced PostgreSQL Features

Description Usage Arguments Details Author(s) See Also Examples

Serialize and write R objects

stow(..., tablename = "rpgstow", schemaname = "rpgstow")

list_stowed(tablename = "rpgstow", schemaname = "rpgstow")

retrieve(objnames, tablename = "rpgstow", schemaname = "rpgstow")

delete_stowed(objnames, tablename = "rpgstow", schemaname = "rpgstow")

stow_image(imagename = "rpgimage", schemaname = "rpgstow")

retrieve_image(imagename = "rpgimage", schemaname = "rpgstow")

`...`	a list of objects or object names
`tablename`	the table for storing objects
`schemaname`	the schema to use
`objnames`	a character vector with object names or regular expressions
`imagename`	a table name for stowing the session image

These functions allow one to write out any R object to a PostgreSQL database and later retrieve them into any R session. The pair stow and retrieve are modeled roughly as save and load.

The contents of ... are handled specially. If a named argument is passed, then the object will be stowed and retrieved with that name. A raw string will not be stowed if it matches the name of any R object; the matching R object will be stowed instead. A vector of strings will however be stowed as is. Object names will be coerced to valid identifiers using make.names. Names must be unique and not collide with any existing object name in the same table.

retrieve assigns the stowed values to the stowed names in the global environment. It will overwrite any variable that has the same name as a stowed object.

The functions retrieve and delete_stowed use regular expression matching as implemented by the PostgreSQL ~ operator.

stow_image and retrieve_image will stow all objects in the current session and retrieve them later. Note that stow_image will overwrite all existing objects stowed within imagename.

Timothy H. Keitt

RApiSerialize

## Not run: 
system("createdb rpgtesting")
connect("rpgtesting")
begin()

stow("test")
list_stowed()
stow("test")
list_stowed()
stow(x = "test")
list_stowed()
x = 1
stow(x)
list_stowed()
stow(y = x)
list_stowed()
rm(x)
retrieve(".*")
print(test)
print(x)
print(y)
delete_stowed(".*")
data(mtcars)
stow(mtcars)
list_stowed()
rm(mtcars)
retrieve("mtcars")
head(mtcars)

rollback()
disconnect()
system("dropdb rpgtesting")
## End(Not run)