I am trying to mask tables of more than 1 million lines, I tried several configurations, but the masking is very slow, there are some recommended settings for streams, theads .. I tried to use LK but there were no gains.
Tables containing 1 or 2 milions of rows are not giant.
We are masking oracle table with hundreds of milions of rows. The mean spead is rough 500k rows per minute.
What is your speed, what is your database? Did you disable triggers, indexes?