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Database Comparison

Comparison of Database Loads

Criteria PostgreSQL DynamoDB Cassandra MongoDB
Data Model Relational (SQL) Key-Value / Document Wide-Column (Keyspace/Table) Document (BSON)
Consistency Model Strong Consistency (ACID) Eventual or Strong (Configurable) Eventual Consistency (Tunable) Eventual or Strong (Configurable)
Write Load Handling Moderate to High Very High Very High High
Write Throughput ~500 to 5,000 writes per second 50,000+ WPS, can scale to millions 50,000+ WPS, can scale to millions ~5,000 to 50,000 writes per second
Read Load Handling Moderate to High Very High Very High High
Read Throughput ~1,000 to 10,000 queries per second 100,000+ QPS, can scale to millions 100,000+ QPS, can scale to millions ~10,000 to 100,000 queries per second
Scalability Vertical Scaling (some Horizontal) Horizontal (Auto-scaling, Serverless) Horizontal (Manual Sharding, Scaling) Horizontal (Sharding, Replica Sets)
Latency Low to Moderate (10-100 ms) Low Latency (Single-digit milliseconds) Low Latency (2-10 ms) Low to Moderate Latency (5-50 ms)
Query Complexity High (SQL, Complex Joins, ACID) Low (Simple Queries, Key-based Access) Moderate (No Joins, Focus on Partition) High (Rich Query Language, Aggregation)
Use Case Focus Transactional Workloads, Analytics Key-Value Operations, High Throughput Write-Intensive, Time-Series, Logging Flexible Schema, Semi-Structured Data

Quantified Load Summary Table

Database Write Load Handling Read Load Handling Latency Best Use Cases
PostgreSQL Moderate to High (500-5,000 WPS) Moderate to High (1,000-10,000 QPS) Low to Moderate (10-100 ms) Transactional systems, complex queries, analytics
DynamoDB Very High (50,000+ WPS, scalable) Very High (100,000+ QPS, scalable) Low (Single-digit ms) High-throughput web apps, IoT, serverless apps
Cassandra Very High (50,000+ WPS, scalable) Very High (100,000+ QPS, scalable) Low (2-10 ms) Real-time data processing, time-series, logging
MongoDB High (5,000-50,000 WPS) High (10,000-100,000 QPS) Low to Moderate (5-50 ms) Flexible schemas, semi-structured data, IoT

Key Takeaways

This breakdown helps in deciding the right database based on quantified load and latency needs for various system design scenarios.