Query

Definitions

1. A request for data from a database or search engine, typically expressed in a structured language like SQL, GraphQL, or a search DSL. As a verb, to query means to interrogate a data source. The difference between a good and bad query can be milliseconds versus minutes.

   In plain English: A question you ask a database — 'show me all users who signed up this month' — written in a special language the database understands.

   Example: "The query joined six tables, had three subqueries, and returned in 12 milliseconds. The DBA wept with pride."

Related Terms

• Consistency
• EHR
• NoSQL
• Schema
• Table
• Transaction
• Time-Series Database
• Vacuum
• Apache Parquet
• IndexedDB
• dbt
• Star Schema
• WAL Replay
• Query Plan
• Index Scan vs Seq Scan
• Upsert
• Database Trigger
• Schema Registry
• DuckDB
• Knex
• Left Join
• MySQL
• Primary Key
• Query Builder
• Query Engine
• Query Optimizer
• RDBMS
• Read Replica
• SQLite
• Turso