Database Technology Selection

Selection Decision Framework

Start with these questions:

1. Primary access patterns? (point lookups, range queries, graph traversals, full-text search)
2. Consistency guarantees? (strong ACID vs eventual consistency)
3. Expected scale? (data volume, concurrent users, read/write ratio)
4. Query complexity? (key-value, complex joins, aggregations, graph traversals)
5. Latency targets? (sub-ms caching, ms OLTP, second-range analytics)
6. Compliance requirements? (GDPR, CCPA, HIPAA, data residency)

RDBMS Selection Guide

PostgreSQL

Strengths: Full ACID, advanced cost-based optimizer, rich indexes (B-tree, Hash, GiST, GIN, BRIN), JSONB | Best for: complex queries, mixed OLTP/analytics, geospatial (PostGIS), JSON+relational hybrid | Scaling: read replicas, partitioning, PgBouncer, Citus for horizontal | Watch: write-heavy needs tuning, vertical scaling limits

Oracle

Strengths: RAC clustering, Data Guard, Flashback, mature optimizer, partitioning | Best for: enterprise OLTP, mission-critical with vendor support, large-scale DW | Scaling: RAC horizontal, partitioning, Active Data Guard read replicas | Watch: licensing cost, vendor lock-in

SQL Server

Strengths: BI integration (SSRS/SSAS/SSIS), Always On AG, TDE built-in, columnstore indexes | Best for: Microsoft ecosystem, BI-heavy, hybrid OLTP/analytics | Scaling: Always On AG for HA, read-scale replicas, partitioning | Watch: Windows-centric, licensing model

MySQL

Strengths: Simplicity, wide adoption, InnoDB ACID, good read performance, easy replication | Best for: web apps, read-heavy, simple transactional systems | Scaling: primary-replica, Group Replication, MySQL Router | Watch: less sophisticated optimizer than PostgreSQL, limited window functions in older versions

NoSQL Selection Guide