Lessons

Introduction. Lost update. Dirty reading. Non-repetitive reading. Reading phantoms.

Read uncommitted Read committed Repeatable read Serializable Transaction isolation support in real DBMS

Emergence of ACID Emergence of Transactions ACID Connectivity

Pro Brewer Consistency Proving the “theorem” of ACID transactions

The Concurrency Problem Transactions Came to Save Us "I" and Other Letters in ACID

How a NoSQL database works. What can NoSQL databases be used for? Types of NoSQL databases. Comparison of SQL (relational) and NoSQL (non-relational) databases.

The emergence of the term NoSQL. Basic characteristics of NoSQL databases. Representation of data in the form of aggregates (aggregates).

Weak ACID properties. Distributed systems, without shared resources (share nothing). NoSQL databases are mostly open source and created in the 21st century.

Description. data model. Data types.

Data distribution. Consistency of data when writing. Consistency of data when reading.

What is sharding? We share the indivisible. A simple example of "how to do it by hand". Amdahl law.

How to shard and slow down N times? About the semi-auto. Absolute perfect automation? What are F()? The price to be paid. Complex/long pain: resharding.