Opens an input or output stream. Returns a handle of type raw to the iterator associated with the stream. You can use the handle to read or write rows and to close the iterator.
If an error occurs, the function returns NULL.
Syntax
tdr.Open( direction, streamno, options )
Syntax Elements
- direction
- Parameter type: characterValid values are as follows:
- "R" (input)
- "W" (output)
- streamno
- Parameter type: integer
The stream number.
- options
- Parameter type: integerHow the stream is manipulated.The only valid value for options is 0, which indicates that individual attributes can be accessed or modified.
Usage Notes
The function opens an input or output stream. Once the stream is opened, rows can be read or written.
You can open an input stream multiple times within a table operator invocation. Each open resets the read position to the start of the stream. If you specify the PARTITION BY clause, opening a stream refers to the rows within a partition. If you do not specify a PARTITION BY clause, opening a stream refers to the rows within the AMP.
You can open an output stream a single time within a table operator invocation.
- Open an input or output stream that is already open.
- Close and reopen an output stream.
- Call this function from the contract function.
Example: Opening an Input Stream
library(tdr); stream <- 0; options <- 0; direction <- "R"; inHandle <- tdr.Open(direction, stream, options);