This article explains how to use Flink CDC together with the CdcTools utility to automatically capture newly created MySQL tables and synchronize both their schema and data to a Doris database in real time, covering the required code, side‑output handling, async execution, and a special delete‑sign field.
MySQL 9.6.0 introduces a modular audit log system, GTID replication overhaul, InnoDB enhancements, hardened security components, richer JSON view controls, logging upgrades, Shell extensions, and numerous bug fixes, all aimed at improving performance, flexibility, and enterprise‑grade reliability.
The article explains that the MySQL PacketTooBigException occurs because the max_allowed_packet setting is too small, shows how to verify the current value, and provides step‑by‑step commands and configuration changes to increase the limit and resolve the error.
When a tens‑million‑row order table needs a new business column, directly running ALTER TABLE can lock the table and disrupt services, so the article explores master‑slave promotion, online DDL tools, schema‑less JSON extensions, and a clever use of an existing redundant column to achieve the change safely.
This article explains three MySQL INSERT variants—INSERT IGNORE, REPLACE INTO, and INSERT ... ON DUPLICATE KEY UPDATE—detailing their syntax, execution behavior, advantages, drawbacks, typical use cases, and practical comparison to help developers choose the most suitable method for handling duplicate or bulk data operations.
The article compares PostgreSQL and MySQL, detailing PostgreSQL’s richer data types, true sequence support, extensible ecosystem, advanced monitoring and replication features, while also acknowledging MySQL’s simplicity and strong points, to help readers decide which database fits their workload best.
This article introduces AgentScope Java 1.0.7, showcases its new features such as Ollama integration, Agent Skill support, and Nacos‑based A2A architecture, and walks through a complete boba‑tea‑shop example that demonstrates a Supervisor‑Worker multi‑agent system, ReActAgent configuration, dynamic MCP registration, MySQL session persistence, Mem0 long‑term memory, and AutoContextMemory compression, plus quick deployment options for local, Kubernetes, and Docker environments.
The article details a MySQL kernel‑level merged‑seckill optimization that replaces traditional queue‑based flash‑sale handling, achieving up to 5.5× higher TPS (up to 23,543 TPS on 128 threads) and sustaining 1.5W+ orders per second, while remaining transparent to applications and preserving compatibility with existing SQL.
This guide shows how to set up MySQL InnoDB ReplicaSet, start MySQL Router 8.2, configure read/write split routing, and verify that reads are directed to replicas while writes go to the primary instance, all without modifying application code.
This article explains MySQL transaction fundamentals, illustrates a banking transfer scenario, details the ACID properties, explores dirty reads, non‑repeatable reads and phantom reads, and compares the four SQL‑92 isolation levels with practical code examples and InnoDB behavior.
The article examines why major Chinese cloud providers and enterprises are building PostgreSQL‑based distributed, cloud‑native databases instead of MySQL, detailing PostgreSQL's richer data types, native sequence support, extensible ecosystem, advanced replication, licensing advantages, and MVCC implementation, while also noting MySQL's remaining strengths.
This guide enumerates frequent misconceptions in SQL performance—from over‑indexing and SELECT * misuse to improper transaction handling and outdated monitoring practices—explains why they hurt efficiency, and provides concrete, version‑aware solutions to optimize queries, schema design, and database operations.
When a critical e‑commerce report took over 20 seconds and triggered a flood of user complaints, a systematic investigation using EXPLAIN, slow‑query logs, and profiling revealed missing indexes, costly joins, and temporary tables, leading to a four‑stage rewrite that reduced execution time to sub‑second performance.
The article compares PostgreSQL and MySQL, highlighting PostgreSQL's richer data types, true sequence support, powerful extensions, built‑in monitoring, advanced replication, open‑source licensing, and MVCC implementation, while acknowledging MySQL's strengths in quick deployment and read‑heavy workloads.
This guide explains how MySQL processes queries in three index‑related stages—Index Key, Index Filter, and Table Filter—showing why keeping operations in the index layer dramatically improves performance and how to design and diagnose indexes effectively.
This article walks through a real e‑commerce MySQL performance crisis, showing how to pinpoint bottlenecks, analyze slow‑query logs, use EXPLAIN, add composite indexes, rewrite SQL, apply partitioning, read/write splitting and caching, and achieve sub‑second response times with 99% CPU reduction.
Meituan's database team created a sandbox‑based capacity assessment platform that replays live traffic, uses accelerated replay to discover performance bottlenecks, and closes the loop with capacity monitoring and automated operations, dramatically improving stability and resource utilization.
This article explains why a naïve full‑table UPDATE on massive MySQL tables can cripple replication, explores deep‑pagination and IN‑clause inefficiencies, and presents a batch‑processing strategy using NO_CACHE, FORCE INDEX, and rate‑controlled scripts to perform safe, high‑performance updates.
This tutorial walks through configuring Canal in cluster mode, enabling MySQL binlog, creating an Elasticsearch index, setting up RocketMQ topics, adjusting Canal properties and instance files, launching services, and implementing a consumer to reliably synchronize MySQL changes into Elasticsearch.
This guide explains why InnoDB fuzzy queries lose indexes, introduces MySQL full‑text search with inverted indexes, shows how to create and use full‑text indexes via CREATE TABLE and ALTER statements, and demonstrates natural language, boolean, and query‑expansion modes with practical SQL examples.
This guide explains how to configure a MySQL client to connect through a bastion host using an SSH tunnel, covering both the standard local connection settings and the jump‑server parameters needed when direct external access is prohibited.
The MySQL Server repository on GitHub has seen no code commits for over three months, sparking concerns about Oracle's strategic shift, recent large‑scale layoffs, and the future sustainability of the community‑driven open‑source database.
This article explains how MySQL implements indexes with B+Tree structures, why they outperform full table scans, the internal layout of leaf and internal nodes, insertion and split mechanics, range‑query processing, and practical optimization tips for clustered and secondary indexes.
This article walks through creating a lightweight material‑management ERP system—including login, dashboard, inventory, inbound and outbound modules—using Vue 3 for the front end and Spring Boot 3, Java 17, MySQL, and MyBatis‑Plus for the back end, highlighting the architecture and development efficiency tricks employed.
This article explains how to overcome MySQL InnoDB Cluster’s IP‑address loss and lack of Proxy Protocol by injecting real client IPs through MySQL Router connection attributes, configuring init_connect, creating a monitoring database and stored procedure, and testing access control for specific user‑IP ranges.
If you need a free, powerful MySQL client to replace Navicat, this guide compares three popular tools—DBeaver, MySQL Workbench, and HeidiSQL—covering their installation steps, key features, and suitability for developers and DBAs.
An experienced MySQL practitioner shares a comprehensive production‑grade design and operations guide, covering primary key selection, normalization, indexing, data types, sharding, foreign key trade‑offs, naming conventions, transaction handling, NULL usage, type safety, read/write splitting, caching, triggers, logging, monitoring, partitioning, security, and a three‑layer summary.
This guide explains why using a plain ALTER TABLE on massive MySQL tables can lock the table and halt services, and presents tool‑based online DDL, native INPLACE options, phased migration strategies, cloud‑DB features, best‑practice checks, monitoring, and rollback techniques to add new columns safely.
Using SELECT * in MySQL queries increases disk I/O, inflates network traffic, and prevents the optimizer from using covering indexes, leading to slower performance and unnecessary resource consumption.
When a core order table with tens of millions of rows needs a new business field, the article explores why a direct ALTER TABLE can lock the table, evaluates master‑slave switching, online DDL tools, extension tables, JSON fields, and a clever reuse of an existing redundant column, providing practical steps and performance insights.
This tutorial walks you through configuring Spring Boot 3.5.5 with ShardingSphere‑JDBC 5.5.2 to achieve database sharding, read‑write splitting, connection‑pool optimization using Druid, and demonstrates the complete code for entities, mappers, services, and controllers, plus verification steps.
This guide walks you through configuring JDK and Maven, installing essential VS Code extensions for Java development, setting up MySQL, creating a Spring Boot project with Maven, and running it using the Cursor IDE, including tips for troubleshooting common version and configuration errors.
This article examines why adding a column to a MySQL table with tens of millions of rows can lock the table, then presents six practical solutions—including native online DDL, PT‑OSC, gh‑ost, dual‑write migration, maintenance downtime, and partition sliding‑window—detailing their procedures, trade‑offs, and suitable scenarios.
This article explains why multi‑source data fragmentation hurts service code, introduces Apache Calcite as a query‑abstraction layer that decouples data location from query logic, and provides step‑by‑step Spring Boot 3 integration, practical code samples, common pitfalls, performance tips, and real‑world scenarios.
MySQL 8.2 introduces native read/write splitting via MySQL Router, allowing automatic routing of reads to replicas and writes to the primary in an InnoDB ReplicaSet without any application changes.
This guide walks you through real‑world MySQL slow‑query problems, showing how to enable logging, analyze execution plans, design single‑ and composite indexes, use partitioning, rewrite queries, and set up monitoring scripts, achieving performance jumps from 800 ms to just 8 ms.
This article analyzes the interview focus on MySQL auto‑increment primary key exhaustion, explains the underlying mechanism, outlines preventive design choices and monitoring, and provides detailed emergency response options, best‑practice recommendations, and common pitfalls for robust database management.
The article explains common pitfalls that cause Spring @Transactional to fail or not roll back, such as incorrect method visibility, final or static modifiers, internal method calls, beans not managed by Spring, multithreading, unsupported database engines, misconfigured propagation, swallowed exceptions, and improper rollback settings, and offers practical solutions for each case.
When MySQL replication falls behind, common culprits include oversized buffer pools, backup‑induced MDL waits, large transactions, slow queries, parallel replication quirks, and network issues, and this guide offers concrete configuration adjustments to restore sync and improve performance.
A legacy project using MySQL 5.7, MyBatis 3.5.0 and mysql‑connector‑java 5.1.26 encounters a "Conversion not supported for type java.time.LocalDateTime" error after switching to MyBatis‑Plus 3.1.1, which is traced to MyBatis 3.5.1 dropping built‑in LocalDateTime handling and the old connector not supporting the type, requiring an upgrade to mysql‑connector‑java 5.1.37 or later.
The article explains that count(1) and count(*) produce identical results and similar execution plans, while count(column) skips NULL values; it also compares their performance under various table schemas and provides a MySQL example demonstrating these differences.
When a MySQL table's auto‑increment primary key approaches its maximum value, you can avoid failures by converting the column to BIGINT, switching to UUIDs, using segmented ID generators, composite keys, adjusting the increment step, or applying database sharding.
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 article shares a collected list of 2023 Tencent backend developer compensation packages—showing total first‑year offers starting above 40 W RMB—followed by detailed explanations of interview questions covering Redis caching, MySQL transactions, hot‑key detection, SQL injection, HTTP/HTTPS differences, API timeout troubleshooting, and microservice migration strategies.
This article explains how improper use of NULL in MySQL columns can lead to serious production incidents, outlines official recommendations against NULL, demonstrates its impact on queries, indexes, and storage, and provides practical guidelines for when to use or avoid NULL values.
This article presents a comprehensive guide to advanced MySQL techniques, covering CTEs, window functions, and query optimization strategies, complete with step‑by‑step code examples, performance tips, and practical demonstrations such as ranking employees and creating materialized views.
This article compiles a detailed comparison of PostgreSQL and MySQL, highlighting PostgreSQL's lack of text‑size limits, better NULL handling, native array and JSON support, built‑in optimistic locking, superior GIS types, MVCC, flexible indexing, robust replication, and overall stability, while also noting the few areas where MySQL still holds an edge.
This article compares the execution‑plan generation, caching, and query‑performance characteristics of Oracle, MySQL, and PostgreSQL, explains how to view plans in each system, and provides practical tips for DBAs to interpret and optimize them effectively.
This article walks through a real‑world case where a batch‑score query API that originally took up to 20 seconds was systematically optimized through index tuning, multithreaded execution, and request‑size limiting, ultimately achieving sub‑second response times.
This guide walks through switching a SpringBoot + MyBatisPlus project from MySQL to PostgreSQL, covering driver setup, JDBC changes, numerous SQL syntax differences, type conversion issues, transaction handling, and provides helper scripts for bulk schema adjustments.
The article recounts a MySQL production incident where an INT auto‑increment column reached its maximum value, causing insert failures, and walks through analysis, three remediation options, a stored‑procedure cleanup, a conversion to BIGINT, performance monitoring, and lessons on concurrency and schema design.
An interview scenario reveals that using a massive IN list (hundreds of thousands of IDs) in MySQL quickly exceeds packet limits, forces full‑table scans, and overloads CPU, while batch IN queries cause network storms; the article dissects these pitfalls and presents three progressive strategies—splitting IN, temporary tables with JOIN, and sharding with stream‑merge—to safely query massive ID sets.
This guide presents a comprehensive collection of MySQL commands covering database management, table creation and alteration, CRUD operations, index handling, transaction control, and essential administration queries, providing clear examples for each task.
When a core order table with tens of millions of rows needs a new business field, executing a plain ALTER TABLE can lock the table and disrupt services, so the article explores master‑slave switching, online schema‑change tools, extension tables, JSON fields, and a clever reuse of an existing redundant column to achieve the change with minimal risk.
This guide presents a comprehensive collection of essential MySQL commands, covering connection management, database creation and selection, table definition and alteration, CRUD operations, query optimization techniques, performance monitoring, and user permission handling, providing clear examples for each command.
This article provides a comprehensive, production‑grade comparison between containerized MySQL on Kubernetes and traditional on‑premises deployments, clarifying core concepts, evaluating elasticity, availability, performance, and operational overhead, and offering concrete best‑practice recommendations, risk considerations, and future trends.
After three months of preparation, a friend secured an offer from SF Express Technology with a base salary of 20k*15—well above the initially expected 15k—and the post shares the full set of interview questions that led to the success.
This article walks through common MySQL performance pitfalls such as inefficient pagination, implicit type conversion, costly UPDATE/DELETE subqueries, mixed sorting, and EXISTS clauses, and demonstrates practical rewrites—including index usage, JOIN conversion, condition push‑down, early LIMIT, and WITH‑clauses—to transform slow queries into millisecond‑level executions.
Faced with minutes‑long posting delays and exploding review costs in a fast‑growing social app, the team introduced 24‑hour shift staffing, a local blacklist stored in MySQL, an in‑memory Trie + Aho‑Corasick matcher, Redis‑driven hot updates and a machine‑audit fallback with a feedback loop, dramatically cutting latency, cost and false‑positives.
This article explains the semantic differences, performance characteristics, and optimal usage scenarios of COUNT(*), COUNT(1), and COUNT(column) in MySQL 8.0+, covering engine behavior, indexing effects, common misconceptions, and practical best‑practice recommendations for interview preparation and real‑world development.
This article walks through creating performance‑test data with Excel and a Python script, troubleshooting cookie handling issues in Java web applications, and building a complete JMeter test plan—including thread groups, CSV data sets, and assertions—to validate an e‑business login flow.
This article explains how MySQL indexes work, enumerates eight common reasons they become ineffective, adds six advanced pitfalls, and provides concrete diagnostic steps and production‑grade optimization techniques to keep queries fast and reliable.
This comprehensive guide walks you through the background, architecture, and technology selection for monitoring, then details step‑by‑step installation of Prometheus, configuring exporters for Linux, MySQL, and Java applications, introduces core PromQL concepts, and shows how to integrate and visualize data with Grafana.
This guide explains how to restore lost MySQL data after accidental DELETE operations by using binary log replay, logical and physical backups, third‑party recovery utilities, and preventive measures such as proper binlog configuration, backup strategies, and permission controls.
The article examines why leading Chinese tech firms are increasingly adopting PostgreSQL instead of MySQL, detailing PostgreSQL‑based products, comparing data‑type support, sequence handling, extensions, monitoring tools, replication mechanisms, licensing, community openness, and MVCC implementation, while also outlining MySQL's limitations.
This guide explains how to reduce MySQL master‑slave replication delay from seconds to sub‑second levels by configuring LOGICAL_CLOCK parallelism, binlog group‑commit tuning, and slave‑side optimizations, presenting concrete parameter settings, performance test results, monitoring scripts, advanced tips, and common pitfalls.
An in‑depth comparison of B+Tree and B‑Tree reveals how their differing node designs affect storage capacity, tree height, disk I/O, range queries, caching, and insert/delete costs, with concrete MySQL InnoDB examples illustrating why B+Tree is the preferred index structure.
When a core order table with tens of millions of rows needs a new field, a naive ALTER TABLE can lock the table and disrupt services, so this article explores master‑slave switching, online DDL tools, schema‑less extensions, and other low‑cost strategies to add the column safely.
This article dissects a non‑typical slow SQL on a massive e‑commerce order table, explains how index structures, B+Tree height, index‑pushdown, and filesort affect performance, and presents a step‑by‑step SOP for analyzing, optimizing, and safely deploying new indexes to eliminate the slowdown.
Using UUIDs as primary keys in MySQL can dramatically degrade performance on large tables due to larger index size, random inserts causing index splits, slower comparisons, and costly index refreshes on updates, but the impact can be mitigated with ordered UUIDs, binary storage, hybrid keys, or table partitioning.
This comprehensive guide walks you through a real‑world MySQL outage, then details step‑by‑step configuration tweaks, InnoDB parameter tuning, connection and thread settings, index design, query rewrites, monitoring scripts, backup strategies, high‑availability replication, and essential tooling to keep your database fast and reliable.
A developer wrote an UPDATE statement that unintentionally used AND inside the SET clause and omitted a WHERE clause, causing MySQL to silently update every row in the table without raising any syntax errors.
When MySQL QPS reaches 10,000, common bottlenecks include CPU saturation, low buffer pool hit rate, connection limits, and lock contention, which can be mitigated through internal tuning, cache interception, read‑write splitting, and horizontal sharding.
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.
This guide walks through practical techniques to push MySQL performance from a few thousand to tens of millions of queries per second, covering single‑node tuning, read/write splitting, caching layers, and horizontal/vertical sharding with concrete configuration tips and architecture diagrams.
This guide explains why MySQL or Java services can suddenly consume 900% CPU, outlines step‑by‑step diagnostics using Linux tools, and provides concrete optimization actions such as killing offending queries, adding indexes, tuning caches, and fixing Java thread loops.
This article explains why MySQL replication lag hurts performance, then details a three‑layer parallel replication strategy—including logical‑clock parallelism, binlog group‑commit tuning, and slave‑side optimizations—provides full my.cnf configurations, performance test results, monitoring commands, utility scripts, common pitfalls, and a summary of the achieved improvements.
This guide equips MySQL ops engineers with practical DML/DQL commands, permission management, transaction handling, and common pitfalls, offering step‑by‑step examples, performance tips and safety checklists to ensure reliable database maintenance and troubleshooting.
This article explains the reasons behind MySQL IN‑clause parameter limits, the performance impact of large IN lists, and provides practical optimization techniques such as splitting queries in application code and using temporary tables with EXISTS to improve efficiency.
The article compares PostgreSQL and MySQL, highlighting PostgreSQL's richer data types, native sequence support, powerful extensions, superior monitoring and replication features, and open‑source licensing, while also noting MySQL's simplicity and ecosystem strengths, to explain why many Chinese enterprises choose PostgreSQL for their core databases.
This guide explains how to identify stored procedures, functions, views, and triggers that still use DEFINER='root'@'%' after renaming the MySQL root account, and provides a Python script to generate and execute the necessary DROP statements across many databases.
This article walks through the strengths, typical use cases, and Python connection code for relational databases (MySQL, PostgreSQL, SQLite), NoSQL stores (MongoDB, Redis, Neo4j), cloud‑native options (DynamoDB), and emerging vector databases such as Milvus, helping you decide which fits your project.
This article shares practical, step‑by‑step guidance from a 15‑year e‑commerce veteran on why, when, and how to optimize databases—including segregation, archiving, query tuning, replication lag detection, parameter tweaks, partitioning, ProxySQL, caching, vertical scaling, and monitoring—to achieve faster, more reliable services.
Choosing between PostgreSQL and MySQL isn’t just a feature checklist; it requires weighing business complexity, team expertise, and future uncertainty, with this guide offering core design philosophies, multi-dimensional capability comparisons, actionable decision paths, and real-world case studies to help you make a production-grade database choice.
This guide explains five ways to persist PHP arrays in a database—including serialize(), JSON encoding, normalized relational tables, comma‑separated strings, and Base64‑encoded data—detailing code examples, required field types, insertion steps, and retrieval techniques.
The article compares PostgreSQL and MySQL across data types, sequence handling, extensions, monitoring tools, replication, licensing, and MVCC implementation, showing why many Chinese tech giants prefer PostgreSQL for complex, high‑availability workloads while acknowledging MySQL’s strengths in simple web scenarios.
This article explains how to build a high‑throughput like and read counter that can handle 100,000 requests per second by layering Redis caching, optional AOF or MySQL persistence, cleaning invalid client requests, and separating business, statistics, and reporting logic.
Discover ten powerful MySQL features—including CTEs, window functions, conditional aggregation, JSON handling, generated columns, and UPSERT tricks—illustrated with real‑world examples and performance tips, so you can write SQL that is more efficient, maintainable, and production‑ready.
When a core order table with tens of millions of rows needs a new column, naïve ALTER TABLE can lock the table and disrupt services, so this article explores safe alternatives such as master‑slave switching, online DDL tools, extension tables, JSON‑based schema‑less designs, and clever reuse of existing redundant fields, complete with practical code snippets and lessons learned.
This article reveals five common MySQL pitfalls—including uncontrolled InnoDB lock granularity, low default IOPS, misleading VARCHAR length handling, undersized InnoDB Buffer Pool, and a fragile Buffer Pool LRU algorithm—and offers practical configuration tips to prevent performance degradation.
This article explains the structural differences between MyISAM and InnoDB storage engines in MySQL, focusing on how each implements primary and secondary indexes using B+ trees, with code examples and diagrams to illustrate clustering versus non‑clustering index designs.
The article shares a seasoned DBA’s firsthand comparison of MySQL and PostgreSQL, covering their histories, performance quirks, real‑world case studies, lock mechanisms, backup strategies, and practical selection guidelines to help developers decide which database best fits their workload.
Learn the differences between MySQL’s copy and in‑place (online) DDL algorithms, how they manage locks, the steps of each process, the new Instant Add Column feature in MySQL 8, and practical strategies—including master‑slave switching—to safely alter tables in production.
An in‑depth guide to MySQL binary logs explains their role in replication, point‑in‑time recovery, auditing, and real‑time data pipelines, covering binlog formats, GTID, encryption, multi‑threaded replication, cleanup strategies, and practical mysqlbinlog commands for monitoring and troubleshooting.
This article details a comprehensive sharding strategy for a high‑traffic message table, explaining why early partitioning is essential, how to design language‑based vertical shards combined with hash‑based horizontal shards, calculate table counts and virtual nodes, and execute a zero‑downtime migration using dual‑writes and gradual traffic rollout.
This article walks through using GPT‑5 and ByteDance’s Trae tool within the VibeCoding workflow to iteratively generate a complete MCP service marketplace front‑end UI, refine it through multiple prompt rounds, produce a PRD, design backend APIs, build a SpringBoot 2.7 project with MyBatis Plus and MySQL, and finally test and deploy the full system.
This guide presents 30 practical MySQL index optimization techniques, covering creation principles, usage tips, performance enhancements, and maintenance strategies, with concrete SQL examples for each rule to help developers improve query efficiency and reduce write overhead.
This comprehensive guide explores MySQL’s layered architecture, core components, storage engines, and detailed SQL language structures, while providing practical commands, optimization techniques, security best practices, and operational procedures for administrators to efficiently manage, tune, and secure MySQL databases.
This article explains the internal mechanics of MySQL 8.0 InnoDB pages, how random primary keys such as UUID cause costly page splits and merges, and provides Java‑level best practices and MySQL commands to optimize primary‑key design for better performance and space utilization.
Learn how to install mydumper on various Linux distributions, use its multithreaded, compressed, and incremental backup features, and deploy a robust Bash script that automates full and incremental MySQL backups, handles encryption, cleanup, logging, notifications, and restoration with myloader.
