Communication channels
The following sections are valid for UDFs and UDTFs. UDA (aggregation) uses a different mechanism for passing user data.
Communication channel is a term describing a method of passing the user-provided code, such as
the nz.fun object, to the R Language Adapter. The R Language Adapter design assumes
that the code to be run is always passed from outside of the R interpreter. A number of channels
have therefore been implemented to allow the code to be passed.
- Passed by a file located in a NFS directory accessible from all R sessions.
- Passed by a base64-encoded string,
Each channel is identified with its predefined name and passed to the R AE through the Dynamic Environment. In this document, it is assumed that Dynamic Environment means passing values in the last parameter of a UDX.
The variety of channels results from different scenarios in which the R Language Adapter might be used on Netezza, such as a pre-registered UDX (filesystem file), code sent from R GUI (workspace file), or R code embedded in SQL queries (plain string).