Firestore vs PostgreSQL

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.

PostgreSQL is a free, open-source database system for storing and scaling complex data workloads. It uses SQL and adds object-relational capabilities, with support for primitive and structured values as well as documents, geometric data, and custom types. Its supported formats include JSON/JSONB, XML, arrays, ranges, and UUIDs. For data integrity, it provides keys, constraints, locks, transactions, savepoints, and SQL-standard transaction isolation levels. Performance tools include multiple index types, query planning and optimization, parallel processing, partitioning, just-in-time expression compilation, and asynchronous I/O. Recovery and availability features include write-ahead logging, several replication methods, point-in-time recovery, and active standbys. Security options include multiple authentication methods, access controls, row- and column-level security, and multi-factor authentication. Extensions, procedural languages, and foreign data wrappers can connect PostgreSQL to other databases or streams. It runs on Linux, macOS, and Windows, and is self-hosted; no managed service is listed. The PostgreSQL License permits use, copying, modification, and distribution without a fee, subject to its conditions.