6616e4d629
Summary: Every time after a compaction/flush finish, we issue user reads to put the table into block cache which includes a couple of IO that read footer, index blocks, meta block, etc. So we implement Prefetch here to reduce IO. Closes https://github.com/facebook/rocksdb/pull/2196 Differential Revision: D4931782 Pulled By: lightmark fbshipit-source-id: 5a13d58dcab209964352322217193bbf7ff78149