The JusDB Database Engineering Blog

An honest comparison of MongoDB and PostgreSQL in 2026 — document model vs relational model, JSONB as a document store, ACID transaction trade-offs, horizontal scaling, licensing, and migration paths.

PostgreSQL 17 is one of the most impactful releases in years. Incremental backups, vacuum improvements, logical replication failover slots, and planner enhancements are all production-critical changes.

Aurora PostgreSQL offers sub-30-second failover and 15 read replicas but costs more per instance and adds per-I/O pricing. Learn when Aurora's HA wins over RDS simplicity with real cost modeling for 2025.

Use PostgreSQL EXPLAIN and EXPLAIN ANALYZE safely, interpret estimates and runtime evidence, and test the smallest change that addresses the real bottleneck.

PostgreSQL's pg_stat_activity view exposes every connection's state — but understanding what 'idle in transaction' means and why it's dangerous requires knowing the full lifecycle of a PostgreSQL backend process.

Use Neon for serverless PostgreSQL — database branching for dev/test, autoscaling, and cost model

PostgreSQL 17 finally adds native incremental backup support — allowing subsequent backups to capture only changed blocks since the last full backup.

A detailed comparison of PgBouncer, Odyssey, and pgcat for PostgreSQL connection pooling — architecture differences, threading models, pool modes, TLS support, and decision criteria for each workload type.

A practical guide to choosing between read replicas and caching layers — replication lag behavior, cache invalidation strategies, thundering herd prevention, tiered read architecture patterns, and decision framework.

Use pgvector for exact and approximate similarity search, relational filters, and hybrid retrieval while measuring recall, latency, storage, and write cost.

How to size your database connection pool correctly — the HikariCP formula, the variables that determine optimal pool size, and the mistakes that cause connection exhaustion or underutilization.

A production guide to zero-downtime database migrations — why ALTER TABLE causes downtime, the Expand-Contract pattern, safe migration patterns for PostgreSQL and MySQL, and tooling with Flyway, Liquibase, pt-osc, and gh-ost.