Use rocksdb as WAL?

This might be an orthogonal idea. But what would be the down side of using rocksDB as WAL for another DB? Thanks

Yes you can use Rocksdb as a WAL . Many applications are using an on-line database with a backup maintained by Rocksdb .

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The downside would be added overhead. RocksDB tries really hard to keep things ordered while providing fast writes and reasonably fast reads. RocksDB itself has a WAL, so data will be written at least twice (to WAL during write and to SST during flush). Compaction will also add unnecessary reads and writes. If you really only need a WAL (not general durability with arbitrary read/write), RocksDB is probably not the best tool for the job.

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