PostgreSQL
Base de datos relacional potente.
Properties: Deterministic, Fast, Pre-image resistant, Avalanche effect. Applications: Data integrity, Password storage, Blockchain linking, Digital signatures.
graph LR
Center["PostgreSQL"]:::main
Rel_mongodb["mongodb"]:::related -.-> Center
click Rel_mongodb "/terms/mongodb"
Rel_model_context_protocol["model-context-protocol"]:::related -.-> Center
click Rel_model_context_protocol "/terms/model-context-protocol"
classDef main fill:#7c3aed,stroke:#8b5cf6,stroke-width:2px,color:white,font-weight:bold,rx:5,ry:5;
classDef pre fill:#0f172a,stroke:#3b82f6,color:#94a3b8,rx:5,ry:5;
classDef child fill:#0f172a,stroke:#10b981,color:#94a3b8,rx:5,ry:5;
classDef related fill:#0f172a,stroke:#8b5cf6,stroke-dasharray: 5 5,color:#94a3b8,rx:5,ry:5;
linkStyle default stroke:#4b5563,stroke-width:2px;
🧒 Explícalo como si tuviera 5 años
Imagine you have a magic machine. No matter what you put inside—a tiny marble or a whole car—it always spits out a small, unique sticker. If you put that same car back in next year, you get the exact same sticker. But if you scratch a tiny [bit](/es/terms/bit) of paint off the car first, the machine gives you a completely different sticker. It's a way for your computer to say: 'Yep, this is exactly the same file you had yesterday'.
🤓 Expert Deep Dive
Technically, a cryptographic [[hash function](/es/terms/hash-function)](/es/terms/cryptographic-hash-function) must possess three properties: 1. Pre-image resistance (hard to find an input for a given output). 2. Second pre-image resistance (hard to find a different input with the same output). 3. Collision resistance (hard to find any two different inputs with the same output). In blockchain, 'SHA-256' is the workhorse of Bitcoin, while 'Keccak-256' is used by Ethereum. Hashes are foundational for 'Merkle Trees' (which allow efficient verification of large datasets) and 'Proof of Work' (where miners must find a random number that, when hashed, starts with a certain number of zeros).