Shard key selection determines data distribution and performance. Poor shard key choices lead to hotspots, uneven load distribution, and performance degradation across the sharded cluster.
Activation functions (ReLU, sigmoid, tanh) add non-linearity, allowing neural networks to approximate non-linear relationships.
The CAP theorem shows it's impossible to guarantee all three: Consistency, Availability, and Partition tolerance simultaneously.
Consensus algorithms (like Raft, Paxos) enable distributed systems to reliably agree on state even with node failures.
BCNF handles edge cases in 3NF where anomalies can occur with composite candidate keys where determinants are not candidate keys themselves.
A B-tree of order m can have at most 2m-1 keys in any node and minimum m-1 keys in non-root nodes.
GraphQL's query language enables clients to specify exact data requirements, eliminating over-fetching and under-fetching issues common in REST.
SQL injection allows attackers to insert malicious SQL code through application inputs, remaining a critical OWASP Top 10 vulnerability despite awareness.
Distributed transactions in microservices require mechanisms like Saga pattern or Two-Phase Commit to maintain consistency across services.
Synchronous replication waits for replicas to acknowledge writes (safer but slower), while asynchronous replication doesn't wait (faster but less safe).