Yi Wu 2cd00773c7 Add bulk create/drop column family API ... Summary: Adding DB::CreateColumnFamilie() and DB::DropColumnFamilies() to bulk create/drop column families. This is to address the problem creating/dropping 1k column families takes minutes. The bottleneck is we persist options files for every single column family create/drop, and it parses the persisted options file for verification, which take a lot CPU time. The new APIs simply create/drop column families individually, and persist options file once at the end. This improves create 1k column families to within ~0.1s. Further improvement can be merge manifest write to one IO. Closes https://github.com/facebook/rocksdb/pull/2248 Differential Revision: D5001578 Pulled By: yiwu-arbug fbshipit-source-id: d4e00bda671451e0b314c13e12ad194b1704aa03		2017-05-07 23:20:46 -07:00
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rocksdb	Add bulk create/drop column family API	2017-05-07 23:20:46 -07:00