Introduced a minimum batch size
Use different batch specifications for the first batch and subsequent batches.
Merge branch 'next' into daniel_batchspec_tuning
Actually set the first_batch flag to false. Apply scaledown only to size, so it can work correctly with with_at_most()
Copy&Paste error, adapted rql test.
This sanity_check caused trouble with partial user-specified batch_confs. It also was unnecessary.
Fixed a comment.
Fixed defects and cleaned up code.
Renamed first_batch to has_sent_batch
Made first_scaledown_factor an int64_t. Simplifies things.
Merge branch 'daniel_batchspec_tuning' into next