Skip to content
SQLPRESS

Databases · Queries · Operations

Databases, queries and the people who run them.

In-depth articles on PostgreSQL, MySQL, SQL Server, Oracle and modern data engineering — written for developers, analysts and database administrators.

Read the archive
SQL Fundamentals3 min read

N+1 Queries: What the ORM Is Actually Doing

One query for the list, then one more for every item in it. The cost is per statement, which is why the profiler shows a fast database and a slow request.

  • #orm
  • #query-optimization
  • #performance

Latest articles

All articles →
PostgreSQL3 min read

Why an Index Is Not Used: the Estimate, Not the Index

An index the planner ignores is usually a row-estimate problem. The fix starts with what the optimizer expected, not with the index definition.

  • #query-optimization
  • #indexing
  • #execution-plans
  • #statistics

Browse by engine

All categories →

Popular tags

All tags →

Start typing to search the archive.