micro-bench | Library for simpe benchmarks | Performance Testing library

Here's an attempt that does two things:

1. Does a single read to get the column names. This is unavoidable, and the only way to know for certain that you get the actual column names (instead of trying to infer it after they cluttered the sampled data); and

2. Prevents the column names from being used in the actual sample, since they will stringify any non-string data present in the data.

Working examples. My intent with these solutions, frankly, is to use the speed of shuf and fread while preserving as much data-safety as possible. I take that latter to be of the utmost importance.

Read the column names and data each time. Less efficient, but if you change datasets often and/or do not want two nearly-identical versions of the file in the directory, then this is a safe way to go.