【Database】Online Transaction Processing (OLTP) vs Online Analytical Processing (OLAP)

Online Transaction Processing

Online transaction processing (OLTP) is a type of database system used in transaction-oriented applications, such as many operational systems. “Online” refers to that such systems are expected to respond to user requests and process them in real-time (process transactions). The term is contrasted with online analytical processing (OLAP) which instead focuses on data analysis (for example planning and management systems).

OLTP systems use a relational database that can do the following:

Process a large number of relatively simple transactions — usually insertions, updates and deletions to data.
Enable multi-user access to the same data, while ensuring data integrity.
Support very rapid processing, with response times measured in milliseconds.
Provide indexed data sets for rapid searching, retrieval and querying.
Be available 24/7/365, with constant incremental backups.

Use

OLTP has also been used to refer to processing in which the system responds immediately to user requests. An automated teller machine (ATM) for a bank is an example of a commercial transaction processing application. Online transaction processing applications have high throughput and are insert- or update-intensive in database management. These applications are used concurrently by hundreds of users. The key goals of OLTP applications are availability, speed, concurrency and recoverability (durability).

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Posted by Wei on 2023-09-19, Last Modified on 2024-09-25

【Distributed System】Data Modeling

Data Model

A data mode is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner.

A data model explicitly determines the structure of data; conversely, structured data is data organized according to an explicit data model or data structure. Structured data is in contrast to unstructured data and semi-structured data.

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Posted by Wei on 2023-09-19, Last Modified on 2023-11-24

【Golang】使用 - Singleflight

Package singleflight provides a duplicate function call suppression mechanism.

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Posted by Wei on 2023-08-29, Last Modified on 2023-09-20

【Java】Data Access Objects (DAO) Pattern

Data Access Objects (DAO)

Code that depends on specific features of data resources ties together business logic with data access logic. This makes it difficult to replace or modify an application’s data resources.

The Data Access Object (or DAO) pattern:

separates a data resource’s client interface from its data access mechanisms
adapts a specific data resource’s access API to a generic client interface

The DAO pattern allows data access mechanisms to change independently of the code that uses the data.

Advantages of DAO pattern

There are many advantages for using DAO pattern. Let’s state some of them here:

While changing a persistence mechanism, service layer doesn’t even have to know where the data comes from. For example, if you’re thinking of shifting from using MySQL to MongoDB, all changes are needed to be done in the DAO layer only.
DAO pattern emphasis on the low coupling between different components of an application. So, the View layer have no dependency on DAO layer and only Service layer depends on it, even that with the interfaces and not from concrete implementation.
As the persistence logic is completely separate, it is much easier to write Unit tests for individual components. For example, if you’re using JUnit and Mockito for testing frameworks, it will be easy to mock the individual components of your application.
As we work with interfaces in DAO pattern, it also emphasizes the style of “work with interfaces instead of implementation” which is an excellent OOPs style of programming.

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Posted by Wei on 2023-08-23, Last Modified on 2023-08-23

【Domain】Case - Movie Theater Ticket Booking System

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Posted by Wei on 2023-08-23, Last Modified on 2023-11-24

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