Apache AsterixDB vs Firestore

Apache AsterixDB is a free, open source, self-managed Big Data Management System for ingesting, storing, indexing, querying and analyzing data. Its Asterix Data Model extends JSON with object-database concepts, while SQL++ and AQL provide declarative queries for semistructured information. Partitioned LSM-based storage supports B+ tree, R-tree and inverted keyword secondary indexes. External datasets can be queried without loading everything into AsterixDB, using adapters for HDFS and local filesystems. Continuous feeds can ingest sources such as Twitter, RSS and sockets. The HTTP query API accepts SQL++ and can return immediate, deferred or asynchronous results. Installation options include NCService, Ansible and Amazon Web Services. The Hyracks parallel runtime has been scale-tested on up to 1000+ cores and 500+ disks. Documentation describes basic transactional concurrency and recovery, and identifies web data warehousing and social data analysis as suitable uses.

Firestore is a fully managed, serverless document database for building AI, web, and mobile applications. It stores flexible JSON data and supports vector search, full-text search, geospatial queries, and ACID transactions on JSON or BSON-compatible documents. Client SDKs for Android, iOS, and web provide real-time updates and automatic syncing for offline access. Firestore can replicate data across multiple regions with strong consistency; multi-region deployments have a stated 99.999% SLA-backed availability. Integrations named for generative AI application work include Google AI Studio, remote MCP, LangChain, and LlamaIndex. Identity controls connect with Cloud IAM, Cloud Identity Platform, and Firebase Authentication. Data is encrypted before it is written to disk, with customer-managed keys available through Cloud KMS. The free quota applies to one database per project and includes 1 GiB of storage, daily read, write, and delete allowances, and 10 GiB monthly outbound transfer. New customers receive $300 in credits, separate from that quota. Server client libraries bypass Firestore Security Rules, so server access needs IAM controls.