Database Insights

Execute MySQL schema migrations safely with the expand-contract pattern, batched backfills, backward-compatible changes, and migration tooling comparison (Flyway, Liquibase, gh-ost).

ClickHouse MergeTree is why ClickHouse queries 1 billion rows in 0.3 seconds. Learn how parts, merges, and sparse indexes work, and how to choose the ORDER BY key, secondary indexes, and MergeTree variants.

When your events table hits 800 million rows, PostgreSQL declarative partitioning becomes essential. Learn range and hash partitioning, automated management with pg_partman, and zero-downtime archival.

Choose jsonb over json for PostgreSQL: GIN indexing, containment operators, path queries, and update operations with || and jsonb_set. Includes performance comparison.

Use MySQL JSON columns effectively with path operators, functional indexes via generated columns, JSON_CONTAINS filtering, and partial updates with JSON_SET.

Compare three PostgreSQL multi-tenant patterns: shared schema with RLS, schema-per-tenant, and database-per-tenant. Includes hash partitioning for shared schema at scale.

Implement least-privilege access in PostgreSQL with role hierarchies, ALTER DEFAULT PRIVILEGES, schema separation, and privilege auditing queries.

Implement PostgreSQL Row Level Security for multi-tenant isolation. Covers USING clauses, WITH CHECK policies, tenant context via set_config, and performance indexing.

TiDB 8.0 is the most production-ready version of the distributed SQL database yet. With improved HTAP, stronger MySQL compatibility, and Resource Groups, it's compelling for teams outgrowing single-node MySQL.

pg_stat_statements tracks every query's total time, call count, and cache hit ratio. Learn to enable it, find your highest-cost queries, hunt for cache misses, and measure the impact of every optimization.

EXPLAIN ANALYZE tells you exactly why your PostgreSQL query is slow, but reading its output is a skill most developers never learn. Learn every node type, identify the five worst plan patterns, and fix them.

MongoDB's flexible schema allows fields to be null, explicitly set to null, or simply absent — and these three states behave differently in queries, aggregations, and indexes.