I've run into this both with 3rd party contrib modules as well as some of my own operations. I'm curious at the various ways to speed up my/contrib batch operations?
Assume they work with nodes (import/update etc) and we're dealing with parsing lists of nodes in the 10,000+ range (although I've had to deal with 15 million rows.. which yes - I'm just screwed on..)
Is it quicker to attach to drupals cron.php job and run "headless"? Using Drush? or is this simply a question of how efficient and quick parsing I can develop my code and there are no outside influences or batch specific optimization tips ...
Currently I've run into operations that (using some rough calculation) could take 24+ hours...
Thanks!