I want to read multiple files parallely into 1 dataframe. But the files have random names and cannot confirm to any pattern (so I can't use wildcard). Also, the files can be in different directories.
If I provide the file names in a list to the dataframe reader, it reads then sequentially.
This reads the files sequentially. What can I do to read the files parallely?
I noticed that spark reads files parallely if provided directly the directory location. How can that be extended to multiple random files?
Suppose if my system has 4 cores, how can I make spark read 4 files at a time?