这会严重影响现有数据库升级或降级时的读取性能和读取 I/O,但不会影响数据正确性 修复了Iterator::Refresh()在执行 DeleteRange() 后读取 stale keys 的错误 Public API changes: 添加了纯虚拟 FilterPolicy::CompatibilityName(),这是修复涉及 SST 元数据中 FilterPolicy 命名的主要性能错误所需要的,而不影响 Fil...
before release 5.7, you'll need to destroy the iterator and recreate it if needed. Since release 5.7, you can call an APIIterator::Refresh()to refresh it. By calling this function, the iterator is refreshed to represent the recent states, and the stale resource pinned previously is released...
etOptions, including requiring an Iterator::Refresh() for an existing Iterator to use the latest opt ions. Fix under counting of allocated memory in the compressed secondary cache due to looking at the com pressed block size rather than the actual memory allocated, which could be larger due to...
RocksDB.newIterator()返回的是一个ArenaWrappedDBIter对象,ArenaWrappedDBIter相当于一个外壳,其持有的DBIter包括了大量的状态变量(上图类结构Iterator最高部分,如当前读取key&value),还持有一个内部迭代器InternalIterator,DBIter的作用是将查询转发给底层InternalIterator,InternalIterator返回的KV是原始的二进制数据,DBI...
Iterator.Prev()is not supported Non prefix-bsed seek is not supported Loading a table more slowly than building an index mmap mode is supported only The common features of PlainTable makes it very suitable for PMem. PlainTable uses mmap (memory mapping file) to prevent page caching, ...
修改链接过程，执行下面的命令，重新编译db_bench，这里主要是为了静态链接必要的动态库，如snappy.a，...
刚刚写入 Rocksdb 的数据在持久化到 WAL 文件后,会先存放在内存中的 MemTable 里,直到达到某些触发条件(比如 memtable 数过多,整体占用内存量过大等)才会后台异步地 flush 持久化到磁盘。WAL 和 memtable 通常是同时进行切换,这样的好处是每个memtable和SST文件的sequence边界和WAL文件的边界可以对齐,在清理不再...
Add Iterator::Refresh(), which allows users to update the iterator state so that they can avoid some initialization costs of recreating iterators. Replace dynamic_cast<> (except unit test) so people can choose to build with RTTI off. With make, release mode is by default built with -fno-...
storm.cluster.mode=local, ui.childopts=-Xmx768m, task.refresh.poll.secs=10, supervisor.childopts=-Xmx256m, task.credentials.poll.secs=30, storm.health.check.timeout.ms=5000, storm.blobstore.replication.factor=3, worker.profiler.command=flight.bash, storm.messaging.netty.buffer.low.watermark=8388...
Introduction This guide is targeted towards users who are already familiar with RocksDB* and provides pointers and system setting for hardware and software that will provide the best performance for most situations. However, please note that we rely on the users to carefully consider these...