Transactions and ACID properties: The four guarantees (atomicity, consistency, isolation, durability) that make a transaction feel like one indivisible unit.
Leads to
CAP theorem: You can't have perfect consistency, availability, and partition tolerance all at once, pick two.
Replication and sharding: Copying data across machines for redundancy versus splitting it across machines for scale.
Related topics
CAP theorem: You can't have perfect consistency, availability, and partition tolerance all at once, pick two.
Replication and sharding: Copying data across machines for redundancy versus splitting it across machines for scale.
NoSQL data models: Alternatives to tables: documents, key-value pairs, wide columns, or graphs, each suited to a different access pattern.