What is a database index?
A database index maps column values to row locations to reduce work during queries.
Lookup and cost
Structures such as B-trees support equality and range lookups. Query plans show whether the index is used; column order matters in composite indexes.
Uses and limitations
Indexes may speed frequent queries but increase write and storage costs. Do not index every column; measure real workloads.
Related topics
What is an SSD?What is computer vision?What is OAuth 2.0?DNSWhat is Content Security Policy?What is computer hardware?What is an API?What is responsive web design?What is event-driven architecture?What is end-to-end encryption?Zero trust architectureWhat is UDP?What is DevOps?What is Bluetooth?What is an IP address?What is a virtual machine?What is FIDO2?What is encryption?What is an operating system?What is TCP?What is database replication?What is a photovoltaic solar panel?What is WebAssembly?What is a data contract?What is retrieval-augmented generation?What is edge computing?What is machine learning?What is Arm architecture?What is a lithium-ion battery?What is a digital signature?What is deep learning?What is a progressive web app (PWA)?What is data backup?What is serverless computing?How does web caching work?What is an SBOM?Artificial intelligenceWhat is RAM?What is 5G?What is open-source software?HEC codeWhat is CORS?What is data encryption?What is a database?What is a firewall?What is NFC?What is natural language processing?What is a service worker?What is model fine-tuning?How are microchips manufactured?