PostgreSQL COPY format is not really CSV but something way easier to
parse. Funnily enough, parsing it as CSV is not that easy, so we add
here a special simple parser for the COPY format.
It should be quite useful too try loading again reject data files from
pgloader after manual fixing, too. It's still missing some documentation
without any good excuse for that, will add soon.
When using LOAD CSV it's possible to load from filename matching a
regular expression, but for that to work the *csv-path-root* needs to be
properly setup at run-time.
With the new internal setting *copy-batch-size* it's now possible to
instruct pgloader to close batches early (before *copy-batch-rows* limit)
when crossing the byte count threshold.
When set to 20 MB it allows the new test case (exhausted) to pass under SBCL
and CCL, and there's no measurable cost when *copy-batch-size* is set to
nil (its default value) in the testing done.
This patch is published without any way to tune the values from the command
language yet, that's the next step once its been proven effective.
