Reads an input record from the in port. 
Passes the input record to the get_filename transform 
function. 
If the get_filename function returns a string that does not 
contain a valid filename, or if the file derived from the 
string is empty or missing, Read Multiple Files proceeds 
according to what is specified in the filename-error, file-
empty, and file-missing parameters. 
If the get_filename function returns a string containing a 
valid filename, Read Multiple Files retrieves the specified 
file. 
 NOTE: The input file specified in the string must be local 
to the machine where Read Multiple Files is running. Note 
also that in multifile layouts, different instances of Read 
Multiple Files can be running on different computers, so 
input filenames referring to directories that exist only on 
particular computers must be partitioned carefully. To use 
relative paths, use the DML function this_partition_path. 

Opens the specified file and reads records from it: 
If an input_type data type is defined in the transform 
package, Read Multiple Files uses this type to read records 
from the file. If you omit input_type, Read Multiple Files 
uses the record type defined on the out port. 
If the filter parameter was set to Range, and the skip-
count parameter is non-0, Read Multiple Files skips the 
specified number of records before reading subsequent 
records from the file. 
If the filter parameter was set to Range, and the read-
count parameter is non-0, Read Multiple Files reads up to 
this maximum number of records from the file. If read_count 
is less than or equal to zero, Read Multiple Files reads 
the remainder of the file. 
Read Multiple Files writes records to the out port. 
If a reformat function is defined in the transform package, 
the component passes each record read from the input file 
to the reformat function, along with the filename. The 
output of the reformat function is written to the out port. 
If you omit a reformat function, but provide an input_type 
data type in the package, the component behaves like a 
Reformat component with no transform package, reading 
records from the file using the input_type, and performing 
any conversion necessary to match the record format on the 
out port. 
If the reject and error ports are connected to flows and 
the reformat transform function returns NULL, Read Multiple 
Files writes an error message to the error port and the 
current record to the reject port. 
Read Multiple Files stops execution of the graph when the 
number of reject events exceeds the value given by the 
following formula:

limit + (ramp * number_of_records_processed_so_far) 

For details, see "Setting limit and ramp for reject events"

If you do not connect flows to either the reject or error 
port, Read Multiple Files does not write an error message 
and discards the rejected record.