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Databases

Exploring Database Isolation Levels
The higher the isolation level, the more anomalies are prevented—but it comes at a cost.
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Consensus
Consensus ensures that all nodes in a distributed system agree on the same value, even in the presence of failures or network partitions.
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Teiva Harsanyi
Consistency Model
Stronger consistency models come with trade-offs: higher overhead and slower performance, while weaker consistency improves speed by tolerating…
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Teiva Harsanyi
Isolation Level
Strong isolation levels ensure data consistency, but at the cost of performance, while weaker isolation levels improve performance but increase the risk…
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Teiva Harsanyi
Transactions
Only transactions with the highest isolation level are fully ACID-compliant, ensuring strict adherence to all ACID properties.
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Teiva Harsanyi
Safety and Liveness
In leader election, avoiding two nodes mistakenly thinking they are the leader is a safety property, while guaranteeing the process eventually completes…
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Teiva Harsanyi
The PACELC Theorem
The PACELC theorem provides a more comprehensive framework for reasoning about distributed systems, ensuring we consider both partition scenarios and…
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Teiva Harsanyi
The CAP Theorem
In practice, partition tolerance is essential because network instability is inevitable in distributed systems. Therefore, CA systems are not viable.
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Teiva Harsanyi
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ACID
It’s also important to distinguish the concept of consistency in ACID and eventual consistency, which instead refers to the principle of convergence.
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Teiva Harsanyi
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