China
Africa
Explore chapters and articles related to this topic
Digital India Digital Economy Using Blockchain Technology
Published in Latesh Malik, Sandhya Arora, Urmila Shrawankar, Vivek Deshpande, Blockchain for Smart Systems, 2022
K.S. Thakre, Gargi Kulkarni, Prajwal Sameer Deshmukh
MySQL is on open-source database, which is mainly a RDBMS, i.e. a relational database management system. As a database server, the primary function of this software is to store and retrieve data as requested by others from end software applications like Java, which may or may not run either on the same computer or on different computer. This can be across the network either in internet or intranet.
Web Databases
Published in Akshi Kumar, Web Technology, 2018
As a primer to the most commonly used databases, we explain a few in the following sections. The discussion is limited to understanding the most popular MySQL (relational), MongoDB (non-relational), and Neo4j (non-relational). MySQL is a popular open-source relational database management system developed, distributed, and supported by Oracle Corporation. It stores data in tables and uses structured query language (SQL) for database access. In MySQL, the database schema is pre-defined based on the requirements and set up rules to govern the relationships between fields in your tables. Related information may be stored in separate tables but associated with the use of joins. In this way, data duplication is minimized.MongoDB is an open source database developed by MongoDB, Inc. It stores data in JSON-like documents that can vary in structure. Related information is stored together for fast query access through the MongoDB query language. MongoDB uses dynamic schemas, which allow the creation of records without first defining the structure, such as the fields or the types of their values. Moreover, the structure of records (which we call documents) can be changed by simply adding new fields or deleting existing ones. This data model gives an ability to represent hierarchical relationships, store arrays, and support other more complex structures easily. Documents in a collection are not required to have an identical set of fields and de-normalization of data is common. MongoDB was designed with high availability and scalability in mind and it includes out-of-the-box replication and auto-sharding (a method for distributing data across multiple machines).Neo4j offers a free, open source Community edition, which is a high-performance, fully ACID-transactional database. The primary advantage of Neo4j is its lightning fast ability to do very complex queries with unlimited depth and weighted connections. You should definitely store graphs like Users and relationships like Friendship or Subscriber inside Neo4j.
Graph-based network generation and CCTV processing techniques for fire evacuation
Published in Building Research & Information, 2021
Jack C. P. Cheng, Keyu Chen, Peter Kok-Yiu Wong, Weiwei Chen, Chun Ting Li
A database is constructed to integrate all required information and store it on a server. The database contains the following items: (1) ‘Node (int)’ denotes the ID of each node of the network, (2) ‘XYZ_node (string)’ denotes the coordinate values of each ‘Node’, (3) ‘Neighbor (int)’ denotes the ID of a node adjacent to the ‘Node’ in the same row, (4) ‘XYZ_neighbor (string)’ denotes the coordinate values of each ‘Neighbor’, (5) ‘Length (int)’ denotes the distance between the ‘Node’ and the ‘Neighbor’ of the same row, (6) ‘Temp_ID (string)’ denotes the ID of a temperature sensor placed between the ‘Node’ and the ‘Neighbor’ of the same row, (7) ‘Temp (int)’ denotes the real-time temperature obtained from corresponding sensor, (8) CO2_ID (string)’ denotes the ID of a CO2 sensor placed between the ‘Node’ and the ‘Neighbor’ of the same row, (9) ‘CO2 (int)’ denotes the CO2 concentration obtained from corresponding sensor, (10) ‘CO_ID (string)’ denotes the ID of a CO sensor placed between the ‘Node’ and the ‘Neighbor’ of the same row, (11) ‘CO (int)’ denotes the CO concentration obtained from corresponding sensor, (12) ‘CCTV_ID (string)’ denotes the ID of a CCTV camera that covers the area between the ‘Node’ and the ‘Neighbor’ of the same row and (13) ‘Density (double)’ denotes the density of pedestrians of the corresponding area. Among all these database information, the coordinates of nodes and lengths of edges are static, while sensor data and flow information are updated in real time. MySQL, which is an open-source relational database management system (Oracle, 2012), is used to construct the database. MySQL supports the SQL language for data query in order to achieve reading and writing of information efficiently. Figure 11 shows part of the database constructed using MySQL. The database can be accessed via the evacuees’ mobile devices (e.g. smart phones and tablets) with a Wi-Fi connection.