orch.unpack

Restores the R objects that were compressed with a previous call to orch.pack.

Usage

orch.unpack(...)

Arguments

. . .

The name of a compressed object.

Usage Notes

This function is typically used at the beginning of a mapper or reducer function to obtain and prepare the input. However, it can also be used externally, such as at the R console, to unpack the results of a MapReduce job.

Consider this data flow:

ORCH client to mapper to combiner to reducer to ORCH client.

If the data is packed at one stage, then it must be unpacked at the next stage.

Return Value

Uncompressed list-type data, which can contain any number and any type of variables

See Also

orch.pack

Example

This code fragment restores the data that was compressed in the orch.pack example:

reducer = function(key, vals) {
     x    <-orch.unpack(vals[[1]])
     r    <-x$qy
     yy   <- x$yy
     nRow <- x$nRows
     .
     .
     .
     }