Introducing full-stack Internet architecture technologies centered on Java
This tutorial demonstrates four methods for multi-table updates in MySQL—INNER JOIN, LEFT JOIN, subquery, and direct multi-table UPDATE—using order and product tables, showing how each handles non-matching rows differently with concrete SQL examples and result comparisons.
This article explains how MySQL uses B+ tree indexes to accelerate queries, detailing their structure, differences from binary search trees, organization around 16KB pages, and why smaller index values reduce tree height and disk I/O for better performance.
This article outlines ten critical MySQL configuration parameters administrators should prioritize after installation, covering InnoDB buffer pool sizing, log file configuration, connection limits, flush methods, query cache disabling, binary logging, and DNS resolution skipping, with practical guidance on safe modification practices and version-specific considerations.
This article explains four approaches to implementing distributed locks with Redis: basic SETNX with expiration, atomic Lua scripts for lock acquire/release, the Redisson Java client with watchdog renewal, and the Redlock algorithm for high-availability multi-master deployments.
This article compares four Redis deployment modes—standalone, master-slave replication, sentinel, and cluster—detailing their architectures, pros, cons, and ideal use cases to help developers choose the best option for scalability and high availability.
MySQL silently trims trailing spaces in string comparisons, causing queries with extra spaces or stored values with spaces to match unexpectedly, but using the BINARY keyword forces a strict byte‑by‑byte comparison to handle such cases.
This guide walks through the limitations of Redis Sentinel, introduces Redis Cluster’s sharding architecture, shows how to configure multiple nodes on a single server, demonstrates cluster creation, key slot calculation, basic CRUD tests, and explains automatic failover behavior when a master node goes down.
This guide introduces MySQL's EXPLAIN command, demonstrates how to create sample order and customer tables, runs various queries, and provides a detailed walkthrough of each column in the execution plan—including id, select_type, table, type, possible_keys, key, key_len, ref, rows, filtered, and extra—plus indexing tips and visual examples.
This article explains MySQL's four transaction isolation levels—Read Uncommitted, Read Committed, Repeatable Read, and Serializable—by creating a simple table, running paired transactions, and showing how each level affects data visibility, concurrency, and potential anomalies such as dirty reads, non‑repeatable reads, and phantom reads.
This tutorial walks through MySQL table joins—INNER, LEFT, RIGHT, and FULL OUTER—using clear diagrams, step‑by‑step SQL examples, and sample data, helping readers understand each join type, its result set, and how to emulate full outer joins in MySQL 5.7.
