Read a PostgreSQL query plan without getting lost
Follow the work through a query plan, compare estimates with actual rows, and learn what to investigate before adding another index.
Understand the tools. Master the fundamentals.
Build better data systems, one practical lesson at a time.
SQL, schemas, and the engines behind your applications.
Explore topicDocuments, key-value data, and flexible ways to model it.
Explore topicFaster reads, thoughtful invalidation, and fewer surprises.
Explore topicTurn data into answers, from your laptop to the cloud.
Explore topicFind the right results in a world of unstructured data.
Explore topicEmbeddings, similarity, and retrieval that makes sense.
Explore topicMove, transform, and connect data across your systems.
Explore topicMigrations, administration, and the tools of the trade.
Explore topicFollow the work through a query plan, compare estimates with actual rows, and learn what to investigate before adding another index.
Read the guideFollow the work through a query plan, compare estimates with actual rows, and learn what to investigate before adding another index.
Build an index around a real access pattern, then use EXPLAIN to understand what it helps—and what it doesn't.
Calculate a running total and rank orders within each customer without collapsing the underlying rows.
Follow a cache hit and miss, then work through invalidation, stale data, and the race conditions hiding between them.
A TTL controls freshness over time. An eviction policy controls what happens under memory pressure. Your cache needs both decisions.
Choose document boundaries from access patterns, growth, and update behavior rather than translating relational tables one-for-one.
From RDS and DynamoDB to Redshift and Athena. Make sense of the services, architecture, and operational decisions.
Explore AWSExplore Azure SQL, Cosmos DB, and Microsoft's analytics ecosystem, including Fabric and its data engineering tools.
Explore AzureConnect Cloud SQL, Spanner, and BigQuery with the tools that ingest, process, and govern your data.
Explore Google CloudThe platform may change. Good engineering principles don't.
Build a working foundation in joins, window functions, and transactions. Small datasets make each idea easy to inspect.
Move from query plans to index design, then understand why analytical workloads ask different questions.
Understand availability, key design, connection budgets, and query costs across AWS, Azure, and Google Cloud.