A beginner’s guide to database multitenancy

Introduction

In software terminology, multitenancy is an architectural pattern which allows you to isolate customers even if they are using the same hardware or software components. Multitenancy has become even more attractive with the widespread adoption of cloud computing.

A relational database system provides a hierarchy structure of objects which, typically, looks like this: catalog -> schema -> table. In this article, we are going to see how we can use each of these database object structures to accommodate a multitenancy architecture.

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A beginner’s guide to Phantom Read anomaly

Introduction

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.

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A beginner’s guide to Non-Repeatable Read anomaly

Introduction

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 Non-Repeatable Read phenomenon.

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A beginner’s guide to CDC (Change Data Capture)

Introduction

In OLTP (Online Transaction Processing) systems, data is accessed and changed concurrently by multiple transactions and the database changes from one consistent state to another. An OLTP system always shows the latest state of our data, therefore facilitating the development of front-end applications which require near real-time data consistency guarantees.

However, an OLTP system is no island, being just a small part of a larger system that encapsulates all data transformation needs required by a given enterprise. When integrating an OLTP system with a Cache, a Data Warehouse or an In-Memory Data Grid, we need an ETL process to collect the list of events that changed the OLTP system data over a given period of time.

In this article, we are going to see various methods used for capturing events and propagating them to other data processing systems.

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