Google Cloud Bigtable vs RocksDB

Google Cloud Bigtable is a managed, low-latency NoSQL database for machine learning, operational analytics, and user-facing applications. It stores structured, semi-structured, and unstructured data in key-value and wide-column formats. SQL querying includes an API with more than 200 functions and support for aggregations, windowing, geospatial and JSON processing, and vector search. Compute scales horizontally, and instances can span up to eight regions with automatic replication between clusters. Google says multi-region instances offer 99.999% availability and protection against a regional failure. Integrations listed include Apache Spark, Hadoop, GKE, Dataflow, Dataproc, Vertex AI Vector Search, BigQuery, and LangChain. Bigtable provides Apache HBase and Cassandra APIs, plus migration tools for HBase, Cassandra, DynamoDB, and Aerospike. Security controls include IAM, customer-managed encryption keys, audit logging, and table-, column-, or row-level access control. Deployment is cloud-based. Google describes its capacity-based low-latency compute as more favorable for larger workloads than small applications. A 10-day trial is available subject to eligibility requirements.

RocksDB is an embeddable, persistent key-value store for applications that need fast storage. It stores keys and values as arbitrary byte arrays, with ordering determined by a comparator chosen by the user. Its log-structured merge design allows configuration of tradeoffs among write, read, and space amplification, and the project describes it as optimized for low-latency storage on flash drives and high-speed disks. The C++ library supports opening and closing databases, reads and writes, merging, and compaction filters. Described uses include database storage engines, application data caches, and embedded workloads. Multi-threaded compactions support databases holding multiple terabytes; the project describes an audience of application servers storing up to a few terabytes on local or remote systems. RocksDB also has a Java wrapper, RocksJava, with artifacts published through Maven. It is free and open source under either GPLv2 or Apache 2.0, at the user's choice. Building requires GCC 11 or later or Clang 10 or later for C++20 support; values must be smaller than 4 GB.