The JusDB Database Engineering Blog

Master MySQL performance optimization with this comprehensive 2025 guide. Learn expert techniques for query tuning, indexing strategies, memory configuration, and InnoDB optimization to achieve 10x database performance improvements.

MySQL 8.4 LTS introduces production-optimized InnoDB defaults out of the box. Learn new default values, performance implications, and upgrade considerations.

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.

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.

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.

MySQL 8.0 introduced EXPLAIN FORMAT=TREE — a hierarchical, human-readable query plan format that reveals join order, access methods, and cost estimates in a way that the traditional tabular EXPLAIN cannot.

MySQL 8.0 introduced multi-valued indexes — allowing you to index individual elements of a JSON array so queries using MEMBER OF or JSON_OVERLAPS can use an index.

Detect query plan regressions in PostgreSQL using auto_explain, pg_hint_plan, and plan baseline management

Identify bloated indexes in PostgreSQL using pgstattuple, REINDEX CONCURRENTLY, and automated monitoring

pg_partman automates PostgreSQL partition lifecycle. This guide covers create_parent(), retention policies, partition pruning, and migrating existing tables without downtime.

Tune PostgreSQL checkpoint frequency, WAL segment size, and bgwriter to maximize write throughput

A deep dive into PostgreSQL JSONB vs JSON storage formats, GIN and B-tree indexing strategies, containment operators, and the performance characteristics that determine which to use for document storage workloads.