--- title: RocksDB 5.4.5 Released! layout: post author: sagar0 category: blog --- ### Public API Change * Support dynamically changing `stats_dump_period_sec` option via SetDBOptions(). * Added ReadOptions::max_skippable_internal_keys to set a threshold to fail a request as incomplete when too many keys are being skipped while using iterators. * DB::Get in place of std::string accepts PinnableSlice, which avoids the extra memcpy of value to std::string in most of cases. * PinnableSlice releases the pinned resources that contain the value when it is destructed or when ::Reset() is called on it. * The old API that accepts std::string, although discouraged, is still supported. * Replace Options::use_direct_writes with Options::use_direct_io_for_flush_and_compaction. See Direct IO wiki for details. ### New Features * Memtable flush can be avoided during checkpoint creation if total log file size is smaller than a threshold specified by the user. * Introduce level-based L0->L0 compactions to reduce file count, so write delays are incurred less often. * (Experimental) Partitioning filters which creates an index on the partitions. The feature can be enabled by setting partition_filters when using kFullFilter. Currently the feature also requires two-level indexing to be enabled. Number of partitions is the same as the number of partitions for indexes, which is controlled by metadata_block_size. * DB::ResetStats() to reset internal stats. * Added CompactionEventListener and EventListener::OnFlushBegin interfaces. * Added DB::CreateColumnFamilie() and DB::DropColumnFamilies() to bulk create/drop column families. * Facility for cross-building RocksJava using Docker. ### Bug Fixes * Fix WriteBatchWithIndex address use after scope error. * Fix WritableFile buffer size in direct IO. * Add prefetch to PosixRandomAccessFile in buffered io. * Fix PinnableSlice access invalid address when row cache is enabled. * Fix huge fallocate calls fail and make XFS unhappy. * Fix memory alignment with logical sector size. * Fix alignment in ReadaheadRandomAccessFile. * Fix bias with read amplification stats (READ_AMP_ESTIMATE_USEFUL_BYTES and READ_AMP_TOTAL_READ_BYTES). * Fix a manual / auto compaction data race. * Fix CentOS 5 cross-building of RocksJava. * Build and link with ZStd when creating the static RocksJava build. * Fix snprintf's usage to be cross-platform. * Fix build errors with blob DB. * Fix readamp test type inconsistency.