Author

YiSu Grain

A fleeting mayfly in the world, a single grain in the boundless sea.

Articles

Likes

Views

Comments

Latest from YiSu Grain

68 recent articles

YiSu Grain

Aug 7, 2026 · Databases

Day 50: Relational Database Normalization – From Functional Dependencies to Normal Form Decomposition

This lesson walks through relational database normalization using a messy enrollment table, showing how to derive functional dependencies, identify candidate keys, detect partial, transitive and BCNF violations, and systematically decompose the schema into student, major, course, teacher and enrollment tables while ensuring lossless joins and dependency preservation.

BCNFSQLdatabase-design

0 likes · 30 min read

Day 50: Relational Database Normalization – From Functional Dependencies to Normal Form Decomposition

YiSu Grain

Aug 7, 2026 · Fundamentals

40 Comprehensive System, Network, and Management Questions – Day 49 Review

A detailed walkthrough of 40 practice questions covering CPU execution time, pipeline theory, cache locality, bus bandwidth, address space, DMA, RAID levels, threading, paging, producer‑consumer synchronization, deadlock conditions, page‑replacement anomalies, networking fundamentals, project‑management metrics, standards, and intellectual‑property basics, complete with explanations and formulas.

CacheComputer ArchitectureNetworking

0 likes · 49 min read

40 Comprehensive System, Network, and Management Questions – Day 49 Review

YiSu Grain

Aug 5, 2026 · Fundamentals

Day 46 – Distinguish Info Systems, ERP/CRM/SCM/BPM and System Engineering

The article explains that an information system comprises people, processes, data, software, hardware and management rules, differentiates TPS, MIS, DSS, ES and OAS, clarifies the distinct responsibilities of ERP, CRM and SCM, contrasts BPM with BPR, and shows how system‑engineering thinking and the verification‑validation distinction guide the five‑stage lifecycle of complex enterprise solutions, using a retail‑chain case study.

BPMCRMERP

0 likes · 36 min read

Day 46 – Distinguish Info Systems, ERP/CRM/SCM/BPM and System Engineering

YiSu Grain

Aug 3, 2026 · Fundamentals

Day45: Mastering Computer Networks – IP Subnetting, Routing, DNS, HTTP/HTTPS & Load Balancing

This guide walks through a real browser request from a medical imaging workstation, explaining how DNS resolves the domain, how IPv4 addresses and CIDR define subnets, how ARP and default gateways determine MAC addresses, how routers apply longest‑prefix matching, and how TCP, TLS, HTTP, and load‑balancing layers work together to deliver the response.

DNSHTTPIP subnetting

0 likes · 43 min read

Day45: Mastering Computer Networks – IP Subnetting, Routing, DNS, HTTP/HTTPS & Load Balancing

YiSu Grain

Jul 30, 2026 · Fundamentals

Day44: Master OS Fundamentals—Processes, Threads, PV, Deadlock, Memory & I/O

This tutorial walks through core operating‑system concepts—including resource management, user vs. kernel mode, processes and threads, state transitions, synchronization, PV (producer‑consumer) semantics, deadlock conditions and prevention, paging address translation, virtual memory, page‑replacement algorithms, file‑system allocation, and I/O models such as blocking, non‑blocking, multiplexing, and asynchronous I/O—using a regional medical imaging platform as a running example.

deadlockio-modeloperating-system

0 likes · 44 min read

Day44: Master OS Fundamentals—Processes, Threads, PV, Deadlock, Memory & I/O

YiSu Grain

Jul 29, 2026 · Fundamentals

Day 43: Understanding Computer Architecture – CPU, Cache, Bus, I/O and RAID

This article explains the core components of a Von Neumann computer, how CPU, registers, cache and main memory interact, the mathematics of pipeline timing, cache locality, bus bandwidth calculation, I/O transfer methods (polling, interrupt and DMA), and the trade‑offs of RAID 0, 1, 5, 6 and 10 with concrete examples and formulas.

BusCPUCache

0 likes · 44 min read

Day 43: Understanding Computer Architecture – CPU, Cache, Bus, I/O and RAID

YiSu Grain

Jul 29, 2026 · Fundamentals

45‑Minute Review: Master the Eight Architecture Types for the Soft Exam

This article guides readers through a 45‑minute review of the eight architecture categories—information‑system, layered, cloud‑native, SOA, embedded, communication, security, and big‑data—showing how to identify the relevant type from a problem statement, combine multiple architectures in a solution, and articulate the problem, solution, rationale, and cost with concrete examples and tables.

Big DataCloud NativeEnterprise Architecture

0 likes · 32 min read

45‑Minute Review: Master the Eight Architecture Types for the Soft Exam

YiSu Grain

Jul 29, 2026 · Industry Insights

How IoT, Edge Computing, AI, and Blockchain Fit Together in a Smart Factory Architecture

This article explains the roles of IoT, edge computing, artificial intelligence, and consortium blockchain in a smart‑factory scenario, showing how perception, transmission, near‑processing, centralized training, and trusted sharing map to architectural layers and business constraints.

Artificial IntelligenceBlockchainEdge Computing

0 likes · 28 min read

How IoT, Edge Computing, AI, and Blockchain Fit Together in a Smart Factory Architecture

YiSu Grain

Jul 28, 2026 · Big Data

Data Warehouse vs Data Lake vs Lambda/Kappa: Choosing the Right Architecture

This article explains why online transaction databases (OLTP) should not be used for multi‑year analytics, outlines the four core characteristics of a data warehouse, details the ETL process, compares star and snowflake schemas, contrasts data warehouses with data lakes, and guides you through selecting Lambda or Kappa architectures using a concrete retail‑store scenario.

Data LakeData WarehouseETL

0 likes · 36 min read

Data Warehouse vs Data Lake vs Lambda/Kappa: Choosing the Right Architecture

YiSu Grain

Jul 28, 2026 · Big Data

Day 39: Big Data Architecture – Distributed Storage, Batch vs Stream Processing, and Compute‑Storage Separation

This lesson explains why a single database cannot scale for massive e‑commerce data, introduces the three core pillars of distributed storage—sharding, replication, and horizontal scaling—covers batch and stream processing differences with Spark, Hive, Flink and Storm, compares compute‑storage integration versus separation, and shows how Kafka, HDFS, Spark and Flink fit together in a real‑time data platform.

Batch ProcessingBig DataCompute-Storage Separation

0 likes · 25 min read

Day 39: Big Data Architecture – Distributed Storage, Batch vs Stream Processing, and Compute‑Storage Separation