DB/RDB
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MySQL ScalingDB/RDB 2020. 2. 23. 20:48
1. Overview By default, the MySQL can be scaled either using Vertical or Hybrid approaches but not fully Horizontal approach. 1.1 What is Scaling, Why and When to use In simple words, Scaling is making your database handle more traffic or load for reading and write queries 2. Master-Slave approach Generally, we tend to create a Master-Slave architecture and route all the write queries on the Mas..
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Dirty ReadDB/RDB 2019. 9. 30. 13:14
1. Overview Database transactions are defined by the four properties known as ACID. The Isolation Level (I in ACID) allows you to trade off data integrity for performance. The weaker the isolation level, the more anomalies can occur, and in this article, we are going to describe the Dirty Read phenomenon. 2. Description 2.1 Phenomenon As previously mentioned, all database changes are applied to ..
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Phantom ReadDB/RDB 2019. 9. 30. 13:11
1. Overview Database transactions are defined by the four properties known as ACID. The Isolation Level (I in ACID) allows you to trade off data integrity for performance. The weaker the isolation level, the more anomalies can occur, and in this article, we are going to describe the Phantom Read phenomenon. 2. Description 2.1 Phenomenon If a transaction makes a business decision based on a set o..
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ACIDDB/RDB 2019. 9. 30. 13:06
1. Overview Transactions are omnipresent in today’s enterprise systems, providing data integrity even in highly concurrent environments. So let’s get started by first defining the term and the context where you might usually employ it. A transaction is a collection of read/write operations succeeding only if all contained operations succeed. 2. Description 2.1 Components 2.1.1 Atomicity Atomicit..
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Transactional locking mechanism and Multi-version concurrency control(MVCC)DB/RDB 2019. 9. 30. 10:26
1. Overview 1.1 Data Concurrency and Consistency Data concurrency: Ensures that users can access data at the same time Data consistency: Ensures that each user sees a consistent view of the data, including visible changes made by the user's own transactions and committed transactions of other users 2. Multiversion Read Consistency (MVCC) 2.1 Oracle Multi-versioning is the ability to simultaneous..
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OLTP, OLAP, and ETLDB/RDB 2019. 9. 11. 14:28
1. Overview 1.1 On-line Transaction Processing (OLTP) OLTP stands for On-line Transaction Processing. OLTP based systems (account, ticket booking, banking systems, money transfer system) are used to perform a large number of short transactions. Almost all of the database queries in OLTP system consist of commands insert, update, delete. Select queries are mainly designed to enable users to selec..
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Explain Query Plan and Query Performance with PostgresDB/RDB 2019. 8. 23. 09:34
1. Overview Let's analyze the query plan with Postgres to enhance performance using explain and analysis. 2. Description 2.1 Optimizer The brain of the database, which interprets queries and determines the fastest method of execution. A single query optimization technique can increase database performance drastically. 2.2 Explain & Analyze 2.2.1 Explain Displaying the execution plan that the Pos..