Summary:
…verwrite_keys. Also changed each no_overwrite_key set to an unordered set, otherwise Knuth shuffle only gets you 2x time improvement, because insertion (and subsequent internal sorting) into an ordered set is the bottleneck.
With this change, each iteration of permutation construction and prefix selection takes around 40 secs, as opposed to 360 secs previously. However, this still means that with the default 10 CF per blackbox test case, the test is going to time out given the default interval of 200 secs.
Also, there is currently an assertion error affecting all blackbox tests in db_crashtest.py; this assertion error will be fixed in a future PR.
Closes https://github.com/facebook/rocksdb/pull/3699
Differential Revision: D7624616
Pulled By: amytai
fbshipit-source-id: ea64fbe83407ff96c1c0ecabbc6c830576939393