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2879 articles · Page 9 of 29
Selected Java Interview Questions
Selected Java Interview Questions
Mar 11, 2024 · Databases

Key MySQL Interview Questions and Answers: Joins, Indexes, Transactions, and Optimization

This article provides a comprehensive overview of essential MySQL interview topics, covering join types, differences among DROP, DELETE, TRUNCATE, UNION vs UNION ALL, CHAR vs VARCHAR, transaction properties and isolation levels, database normalization, index types and usage, query execution flow, storage engine differences, and practical SQL optimization techniques.

IndexOptimizationSQL
0 likes · 20 min read
Key MySQL Interview Questions and Answers: Joins, Indexes, Transactions, and Optimization
macrozheng
macrozheng
Mar 11, 2024 · Databases

Discover Chiner: A Modern Open‑Source Database Design Tool

This article introduces the open‑source database design tool Chiner, compares it with PowerDesigner, and provides step‑by‑step guidance on installation, core concepts, table management, relationship diagram creation, and import/export features for efficient database modeling.

SQLchinerentity modeling
0 likes · 9 min read
Discover Chiner: A Modern Open‑Source Database Design Tool
Efficient Ops
Efficient Ops
Mar 10, 2024 · Databases

How Machine Learning Can Automate MySQL Index Optimization

This article explains how applying machine learning to database operations—specifically AIOps for MySQL—can automate index recommendation by parsing SQL, extracting semantic and statistical features, generating candidate index combinations, and training an XGBoost model to predict optimal indexes, reducing reliance on manual DBA work.

AIOpsMachine LearningMySQL
0 likes · 10 min read
How Machine Learning Can Automate MySQL Index Optimization
Java Tech Enthusiast
Java Tech Enthusiast
Mar 10, 2024 · Databases

Why IN and NOT IN Should Be Avoided in SQL Queries

Because IN and NOT IN often bypass indexes on large tables, can yield incorrect results when column names differ or NULL values are present, and may cause severe performance penalties, they should be replaced with EXISTS/NOT EXISTS subqueries or appropriate JOINs, reserving IN only for small literal lists.

IN ClausePerformanceQuery Optimization
0 likes · 4 min read
Why IN and NOT IN Should Be Avoided in SQL Queries
Aikesheng Open Source Community
Aikesheng Open Source Community
Feb 29, 2024 · Databases

Optimizing Nested-Loop Join Performance in OceanBase: Analysis, Rewrites, and Results

This article analyzes a slow Join query on OceanBase 3.2.3.3, examines execution plans and table statistics, proposes two rewrite methods—adding a filter condition and using a hash‑join hint—and demonstrates how these changes reduce execution time from over 500 seconds to just a few seconds.

Database PerformanceNested LoopOceanBase
0 likes · 12 min read
Optimizing Nested-Loop Join Performance in OceanBase: Analysis, Rewrites, and Results
Liangxu Linux
Liangxu Linux
Feb 28, 2024 · Databases

Master MySQL InnoDB Full-Text Search: Indexes, Queries, and Advanced Techniques

This article explains how MySQL InnoDB implements full‑text search, covering the underlying inverted index structures, how to create and drop full‑text indexes, the MATCH…AGAINST syntax, and detailed examples of natural language, boolean, and query‑expansion search modes with practical SQL demos.

Boolean ModeFull-text SearchMySQL
0 likes · 12 min read
Master MySQL InnoDB Full-Text Search: Indexes, Queries, and Advanced Techniques
JD Tech
JD Tech
Feb 28, 2024 · Databases

Detecting and Monitoring Database Deadlocks with EasyBI: A Practical Case Study

This article recounts how a production database deadlock was uncovered during testing, explains the use of the EasyBI monitoring tool to collect and visualize error and claim statistics, and shares the step‑by‑step configuration, analysis, and lessons learned for preventing similar issues in future systems.

DatabaseDeadlockEasyBI
0 likes · 8 min read
Detecting and Monitoring Database Deadlocks with EasyBI: A Practical Case Study
DataFunTalk
DataFunTalk
Feb 28, 2024 · Big Data

Building a Data System with Apache Arrow: Design, Modeling, and Execution

This article explains why new data systems are needed, introduces Apache Arrow and its columnar in‑memory format, describes read‑time modeling and dynamic schema handling, and shows how Arrow can be used to build a complete data processing pipeline with indexing, SQL planning, and zero‑copy data exchange.

Apache ArrowBig DataData Systems
0 likes · 20 min read
Building a Data System with Apache Arrow: Design, Modeling, and Execution
dbaplus Community
dbaplus Community
Feb 25, 2024 · Databases

How a Simple UPDATE Wiped My Production Database—and the Lessons I Learned

After a weekend support ticket led to a reckless UPDATE that erased all orders in a production PostgreSQL database, the author details the rapid recovery steps, analyzes the human errors behind the disaster, draws lessons from Chernobyl, and outlines concrete post‑mortem improvements to prevent future data loss.

RecoverySQLdatabases
0 likes · 7 min read
How a Simple UPDATE Wiped My Production Database—and the Lessons I Learned
Open Source Tech Hub
Open Source Tech Hub
Feb 21, 2024 · Databases

Mastering MySQL JSON: Storage, Queries, and Best Practices

This guide explains MySQL's native JSON data type, its storage format, advantages over text columns, and provides step‑by‑step examples for creating tables, inserting JSON, querying with path operators, using built‑in functions, and handling conditional searches.

Data TypesMySQLSQL
0 likes · 10 min read
Mastering MySQL JSON: Storage, Queries, and Best Practices
MaGe Linux Operations
MaGe Linux Operations
Feb 21, 2024 · Databases

How to Deploy Fine-Grained Disaster Recovery for GaussDB DWS on Cloud

This guide explains step‑by‑step how to manually set up fine‑grained disaster recovery for GaussDB(DWS) in a cloud‑based dual‑cluster environment, covering preparation, configuration files, backup/restore operations, verification, and removal to achieve reliable, cost‑effective data protection.

GaussDBSQLcloud
0 likes · 20 min read
How to Deploy Fine-Grained Disaster Recovery for GaussDB DWS on Cloud
Programmer DD
Programmer DD
Feb 19, 2024 · Backend Development

How to Build a Full‑Text Search API with Spring Boot and PostgreSQL

This guide explains how to implement a searchable user‑story interface using PostgreSQL tables with btree and gin indexes, Java record models, Spring Boot data access, and REST controllers to support range and full‑text queries efficiently.

Full-text SearchJavaPostgreSQL
0 likes · 9 min read
How to Build a Full‑Text Search API with Spring Boot and PostgreSQL
php Courses
php Courses
Feb 19, 2024 · Backend Development

Using PHP mysqli_query to Execute MySQL Queries

This article explains how to use PHP's mysqli_query function to perform MySQL operations such as SELECT, INSERT, UPDATE, and DELETE, providing a step‑by‑step example that creates a connection, runs a SELECT query, processes results, and handles errors and cleanup.

DatabaseMySQLPHP
0 likes · 4 min read
Using PHP mysqli_query to Execute MySQL Queries
MaGe Linux Operations
MaGe Linux Operations
Feb 12, 2024 · Databases

Why Hash Join Beats Nested Loop Join and When It Fails

This article explains why hash joins usually outperform nested‑loop joins, how to force hash joins in SQL, the data‑type restrictions that prevent hash joins, and practical tips for optimizing join performance in TD and Oracle compatibility modes.

Data TypesHash JoinNested Loop
0 likes · 6 min read
Why Hash Join Beats Nested Loop Join and When It Fails
Laravel Tech Community
Laravel Tech Community
Feb 4, 2024 · Databases

Understanding Full-Text Search and Inverted Indexes in MySQL InnoDB

This article explains how MySQL InnoDB implements full‑text search using inverted indexes, covers the creation and usage of FULLTEXT indexes, demonstrates various MATCH…AGAINST query modes such as natural language, boolean, and query expansion, and shows how to manage and delete full‑text indexes with practical SQL examples.

Boolean ModeMySQLQuery Expansion
0 likes · 10 min read
Understanding Full-Text Search and Inverted Indexes in MySQL InnoDB
Open Source Tech Hub
Open Source Tech Hub
Feb 4, 2024 · Backend Development

How to Build a Secure SQL Query Tool for Private Deployments

This article explains why a SQL query tool is essential for on‑premise systems, describes the challenges of remote access and data safety, and provides a step‑by‑step implementation covering frontend encryption, backend whitelist checks, decryption, and query execution with code examples.

EncryptionJavaScriptPHP
0 likes · 8 min read
How to Build a Secure SQL Query Tool for Private Deployments
DataFunSummit
DataFunSummit
Jan 31, 2024 · Big Data

iQIYI Magic Mirror: Evolution of a Big Data Analysis Platform

iQIYI's Magic Mirror platform, evolving from 1.0 to 3.0, addresses the growing data analysis demands of the internet industry by empowering self‑service analytics, introducing multi‑stage architectures, advanced computation engines, customizable SQL, and visual dashboards, thereby improving efficiency, scalability, and data security for business users.

Big DataSQLSelf‑service analytics
0 likes · 18 min read
iQIYI Magic Mirror: Evolution of a Big Data Analysis Platform
DataFunTalk
DataFunTalk
Jan 29, 2024 · Big Data

Case Study: Deploying RisingWave for Real-Time Stream Processing in a Large-Scale Quantitative Hedge Fund

An ultra‑large hedge fund with over $10 billion AUM replaced ksqlDB and Flink with RisingWave, leveraging its PostgreSQL‑compatible streaming SQL to achieve sub‑10 ms latency, lower learning and operational costs, rich connectors, advanced operators, and comprehensive observability for real‑time trade data processing.

Data IntegrationRisingWaveSQL
0 likes · 10 min read
Case Study: Deploying RisingWave for Real-Time Stream Processing in a Large-Scale Quantitative Hedge Fund
Architect's Guide
Architect's Guide
Jan 29, 2024 · Databases

Performance Comparison of IN vs JOIN in MySQL Queries

This article experimentally compares the efficiency of using IN clauses versus JOIN operations in MySQL by testing small, medium, and large datasets, measuring query costs, execution times, and highlighting the scalability limits of IN statements.

DatabaseJOINMySQL
0 likes · 8 min read
Performance Comparison of IN vs JOIN in MySQL Queries
Liangxu Linux
Liangxu Linux
Jan 28, 2024 · Databases

Master MySQL Date Functions: CURDATE, NOW, DATE_FORMAT, DATEDIFF, and More

This guide explains MySQL’s most useful date and time functions—including CURDATE(), NOW(), DATE_FORMAT(), DATEDIFF(), DATE_ADD(), DATE_SUB(), and DATE()—with clear syntax examples and sample results, helping developers manipulate temporal data efficiently in their databases.

DatabaseDate FunctionsMySQL
0 likes · 4 min read
Master MySQL Date Functions: CURDATE, NOW, DATE_FORMAT, DATEDIFF, and More
Liangxu Linux
Liangxu Linux
Jan 28, 2024 · Databases

Master MySQL Date Functions: CURDATE, NOW, DATE_FORMAT, and More

This guide walks you through the most commonly used MySQL date functions—CURDATE, NOW, DATE_FORMAT, DATEDIFF, DATE_ADD, DATE_SUB, and DATE—explaining their purpose, syntax, and example results so you can handle date and time data efficiently in your databases.

CURDATEDATEDIFFMySQL
0 likes · 4 min read
Master MySQL Date Functions: CURDATE, NOW, DATE_FORMAT, and More
Rare Earth Juejin Tech Community
Rare Earth Juejin Tech Community
Jan 26, 2024 · Databases

Easy-Query: One of the Best Java ORM Libraries

Easy-Query is a Java ORM framework offering strong-typed, database-agnostic CRUD operations, complex SQL generation, multi-table joins, group awareness, and extensive function support, demonstrated through numerous code examples covering queries, joins, subqueries, pagination, and advanced features like enum handling and anonymous type alternatives.

DatabaseEasy-QueryJava
0 likes · 16 min read
Easy-Query: One of the Best Java ORM Libraries
Liangxu Linux
Liangxu Linux
Jan 24, 2024 · Databases

How MySQL Executes a SELECT Query: From Connection to Result

This article explains the complete lifecycle of a MySQL SELECT statement, covering the server and storage‑engine layers, the roles of the connector, query cache, parser, optimizer and executor, and provides concrete command‑line and SQL examples.

Database ArchitectureMySQLOptimizer
0 likes · 10 min read
How MySQL Executes a SELECT Query: From Connection to Result
Senior Brother's Insights
Senior Brother's Insights
Jan 22, 2024 · Databases

Mastering SQL: Clear Guide to DDL, DML, DQL, DCL, and TCL Commands

An in‑depth tutorial walks through the five core SQL language families—DDL, DML, DQL, DCL, and TCL—explaining their purposes, key commands, and practical examples, while highlighting differences and usage tips for database schema definition, data manipulation, querying, permission control, and transaction management.

DCLDDLDML
0 likes · 11 min read
Mastering SQL: Clear Guide to DDL, DML, DQL, DCL, and TCL Commands
dbaplus Community
dbaplus Community
Jan 21, 2024 · Databases

How to Use ES|QL in Elasticsearch 8.11: DSL vs SQL Queries Compared

This guide demonstrates how Elasticsearch 8.11's new ES|QL query language matches the traditional DSL syntax, covering basic searches, sorting, wildcard matching, aggregations, REST API nuances, and practical examples that show equivalent DSL and ES|QL statements with visual results.

AggregationDSLES|QL
0 likes · 6 min read
How to Use ES|QL in Elasticsearch 8.11: DSL vs SQL Queries Compared
Java High-Performance Architecture
Java High-Performance Architecture
Jan 19, 2024 · Backend Development

Mastering Data Isolation in Java: MyBatis Interceptor & Custom Annotations

This article walks through the challenges of environment‑specific data isolation in a Java project, explains why adding an env column to every table is impractical, and presents a clean solution using a MyBatis interceptor that rewrites SQL and custom annotations to control filtering, ensuring safe, maintainable code across pre‑release, gray, and production environments.

Custom AnnotationData IsolationInterceptor
0 likes · 12 min read
Mastering Data Isolation in Java: MyBatis Interceptor & Custom Annotations
Aikesheng Open Source Community
Aikesheng Open Source Community
Jan 15, 2024 · Databases

What Software Developers Should Know About SQL

This article explains essential SQL concepts and common pitfalls—such as overusing SELECT *, choosing appropriate data types, respecting column order, handling NULL differences, leveraging database processing, using connection pools, and applying batch operations—to help developers write efficient, cost‑effective queries and advance their careers.

Data TypesJDBCPerformance
0 likes · 11 min read
What Software Developers Should Know About SQL
MaGe Linux Operations
MaGe Linux Operations
Jan 12, 2024 · Databases

Master MySQL Flow Control: IF, CASE, LOOP, WHILE, REPEAT & LEAVE Explained

This guide explains MySQL stored procedure flow‑control constructs—including IF, CASE, LOOP, WHILE, REPEAT, LEAVE and ITERATE—detailing their syntax, usage patterns, and practical examples such as salary adjustments and conditional logic, helping developers implement complex database operations efficiently.

DatabaseFlow ControlMySQL
0 likes · 19 min read
Master MySQL Flow Control: IF, CASE, LOOP, WHILE, REPEAT & LEAVE Explained
Code Ape Tech Column
Code Ape Tech Column
Jan 12, 2024 · Databases

MySQL Event Scheduler: Concepts, Operations, and Practical Examples

This article explains MySQL event scheduler fundamentals, including enabling/disabling the scheduler, creating, altering, and dropping events, scheduling syntax, and practical examples such as generating real-time sales data and periodic statistics, providing code snippets and best‑practice guidance for database automation.

Data GenerationDatabase AutomationEvent Scheduler
0 likes · 9 min read
MySQL Event Scheduler: Concepts, Operations, and Practical Examples
Aikesheng Open Source Community
Aikesheng Open Source Community
Jan 11, 2024 · Databases

Step-by-Step Guide to Managing SQL Releases with SQLE

This article provides a detailed walkthrough of using the SQLE platform to create users, configure data sources, submit SQL tickets, perform reviews, and execute releases, illustrating each step with screenshots and practical tips for effective database change management.

Database ManagementMySQLSQL
0 likes · 7 min read
Step-by-Step Guide to Managing SQL Releases with SQLE
php Courses
php Courses
Jan 10, 2024 · Backend Development

How to Query MySQL with PHP and Return Results as an Array

This tutorial demonstrates how to set up a PHP script that connects to a MySQL database, executes a SELECT query, stores the result rows in an array, and displays the data in an HTML table using loops such as while and foreach.

MySQLPHPSQL
0 likes · 5 min read
How to Query MySQL with PHP and Return Results as an Array
NetEase LeiHuo UX Big Data Technology
NetEase LeiHuo UX Big Data Technology
Jan 9, 2024 · Artificial Intelligence

Accelerating Recommendation System Development with MindsDB

The article explains how the data team adopted the open‑source machine‑learning platform MindsDB to simplify data integration, enable SQL‑based model training and inference, manage model versions, and dramatically shorten recommendation system development cycles, achieving up to 30% efficiency gains.

Data IntegrationMachine LearningMindsDB
0 likes · 5 min read
Accelerating Recommendation System Development with MindsDB
ITPUB
ITPUB
Jan 8, 2024 · Databases

How I Cut an 8‑Second SQL Query to 0.7 Seconds: Step‑by‑Step Optimization

This article walks through a real‑world case of a slow MySQL query that took 8 seconds, explains how the original use of EXISTS and NOT EXISTS caused performance bottlenecks, and details two successive rewrites—first using JOIN + GROUP BY, then replacing NOT EXISTS with NOT IN—bringing execution time down to 0.7 seconds while highlighting key indexing and testing lessons.

DatabaseMySQLPerformance Tuning
0 likes · 7 min read
How I Cut an 8‑Second SQL Query to 0.7 Seconds: Step‑by‑Step Optimization
Aikesheng Open Source Community
Aikesheng Open Source Community
Jan 8, 2024 · Databases

AIKOS Open Source Community Weekly Newsletter – SQLE Release, Community Updates, and Selected Database Articles

This newsletter announces the SQLE 3.2401.0-pre1 release with automatic data masking, shares recent community development work, outlines upcoming plans, and curates several technical articles covering MySQL EXPLAIN enhancements, transaction fundamentals, hardware considerations for database stability, consistent backup techniques, and efficient JDBC connection testing.

CommunityDatabaseMySQL
0 likes · 6 min read
AIKOS Open Source Community Weekly Newsletter – SQLE Release, Community Updates, and Selected Database Articles
Java High-Performance Architecture
Java High-Performance Architecture
Jan 5, 2024 · Databases

Why Manticore Search Could Replace Elasticsearch: 10× Faster, Open‑Source DB

Discover how Manticore Search, an open‑source C++‑based high‑performance search engine, claims to outperform Elasticsearch by up to 15‑times, offering cost‑effective, multi‑threaded full‑text search, SQL compatibility, Docker deployment, and extensive language client support for diverse data workloads.

C++DockerElasticsearch alternative
0 likes · 6 min read
Why Manticore Search Could Replace Elasticsearch: 10× Faster, Open‑Source DB
Selected Java Interview Questions
Selected Java Interview Questions
Dec 27, 2023 · Databases

Fast Database Migration Methods: Logical, File, and Physical Approaches with MySQL

This article explains three MySQL data‑migration techniques—logical migration using mysqldump, file‑based migration with SELECT … INTO OUTFILE and LOAD DATA INFILE, and physical migration by copying InnoDB files—detailing commands, performance considerations, and practical steps for each method.

Database MigrationFile MigrationLogical Migration
0 likes · 12 min read
Fast Database Migration Methods: Logical, File, and Physical Approaches with MySQL
DataFunTalk
DataFunTalk
Dec 27, 2023 · Big Data

Apache Flink 2023: Core Technical Achievements and Future Directions

The article reviews Apache Flink's rapid development over the past decade, highlighting its 2023 community growth, SIGMOD award, major releases, streaming SQL enhancements, incremental checkpointing, batch maturity, cloud‑native scaling, and integration with the emerging Lakehouse architecture.

Apache FlinkBig DataCheckpoint
0 likes · 11 min read
Apache Flink 2023: Core Technical Achievements and Future Directions
ITPUB
ITPUB
Dec 25, 2023 · Big Data

Unlock Complex Data Scenarios with Simple MaxCompute SQL Techniques

This article shows how flexible, divergent thinking combined with basic MaxCompute (ODPS) SQL syntax can solve complex data problems such as generating sequences, splitting intervals, performing permutations and combinations, and analyzing continuous activity, providing step‑by‑step examples, SQL code snippets, and practical results.

Data ProcessingMaxComputeSQL
0 likes · 24 min read
Unlock Complex Data Scenarios with Simple MaxCompute SQL Techniques
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Dec 22, 2023 · Databases

Understanding NULL Values in MySQL

This article explains the nature of NULL in MySQL, demonstrates why comparisons with = or != fail, shows the correct IS NULL/IS NOT NULL syntax, and discusses how NULL behaves with DISTINCT, GROUP BY, ORDER BY, and aggregate functions.

AggregationDatabaseMySQL
0 likes · 6 min read
Understanding NULL Values in MySQL
Programmer DD
Programmer DD
Dec 22, 2023 · Backend Development

Master Spring Boot 3.2 JdbcClient: Fluent API for Simple DB Operations

This guide introduces Spring Boot 3.2's new JdbcClient, explains how to add the dependency, inject it, and perform fluent, chainable CRUD operations—including queries by ID, custom conditions, named parameters, map parameters, row mapping, and inserts—while highlighting its advantages over traditional ORM tools.

DatabaseFluent APIJava
0 likes · 7 min read
Master Spring Boot 3.2 JdbcClient: Fluent API for Simple DB Operations
Aikesheng Open Source Community
Aikesheng Open Source Community
Dec 20, 2023 · Databases

Analyzing and Resolving Slow Query Plan Issues in OceanBase 3.2.3

This article presents a step‑by‑step investigation of a SELECT statement that became 1000× slower in OceanBase 3.2.3 BP8, explains why the optimizer chose an inefficient I5 index, describes the plan‑expiration logic, and provides reproducible scripts and practical recommendations for fixing the problem.

OceanBasePerformance TuningPlan Cache
0 likes · 19 min read
Analyzing and Resolving Slow Query Plan Issues in OceanBase 3.2.3
Aikesheng Open Source Community
Aikesheng Open Source Community
Dec 14, 2023 · Databases

SQLE 3.0 Installation Guide: RPM and Docker Deployment

This article provides a step‑by‑step guide for installing the open‑source SQLE 3.0 SQL quality management platform using both RPM packages and Docker containers, covering environment preparation, configuration file adjustments, service startup, common issues, and troubleshooting tips.

DatabaseDockerInstallation
0 likes · 11 min read
SQLE 3.0 Installation Guide: RPM and Docker Deployment
Data Thinking Notes
Data Thinking Notes
Dec 12, 2023 · Artificial Intelligence

Boosting Text‑to‑SQL Accuracy with Prompt Engineering and LLMs

This article examines the challenges of LLM‑based Text‑to‑SQL such as hallucinations, data‑security risks, and user input errors, and presents prompt‑engineering strategies, fine‑tuning comparisons, prompt types, code examples, and experimental results to improve reliability and cost‑effectiveness.

Artificial IntelligenceLLMLangChain
0 likes · 15 min read
Boosting Text‑to‑SQL Accuracy with Prompt Engineering and LLMs
StarRocks
StarRocks
Dec 12, 2023 · Databases

How StarRocks Enables Real-Time Updates in Analytical Databases

The article explains why analytical databases struggle with real‑time data changes due to columnar storage, complex indexes and distributed processing, and then details StarRocks' primary‑key model, adaptive update mode, bitmap indexes, row/column partial updates, and practical SQL upsert techniques to achieve low‑latency updates without sacrificing query performance.

Partial UpdateReal-Time UpdateSQL
0 likes · 15 min read
How StarRocks Enables Real-Time Updates in Analytical Databases
Architect
Architect
Dec 11, 2023 · Backend Development

How to Integrate Dataway into a Spring Boot Project – A Step‑by‑Step Guide

This article walks through the complete process of adding Dataway to a Spring Boot application, covering Maven dependencies, configuration properties, database schema creation, data source setup, Hasor module integration, enabling Hasor in Spring, and finally creating and testing API endpoints using both SQL and DataQL, all illustrated with concrete code snippets and log output.

API ConfigurationDataQLDataway
0 likes · 16 min read
How to Integrate Dataway into a Spring Boot Project – A Step‑by‑Step Guide
Python Programming Learning Circle
Python Programming Learning Circle
Dec 7, 2023 · Fundamentals

Practical Python Implementation of Credit Card User Profiling Using SQL and Data Visualization

This tutorial demonstrates a complete workflow for building credit‑card user profiles by first extracting and transforming the KDD99 dataset with SQL, then applying Python libraries such as pandas, matplotlib, and seaborn to perform descriptive statistics and produce visualizations of demographic, transaction, and financial characteristics.

PythonSQLSeaborn
0 likes · 12 min read
Practical Python Implementation of Credit Card User Profiling Using SQL and Data Visualization
Efficient Ops
Efficient Ops
Dec 6, 2023 · Databases

When and How to Use MySQL Locks: A Deep Dive into Explicit and Implicit Locking

This article explains MySQL's explicit and implicit locking mechanisms, illustrates how transaction isolation levels affect lock scope, provides practical SQL examples for various scenarios, and offers guidelines on when to apply pessimistic locks versus optimistic approaches to maintain database performance.

DatabaseMySQLSQL
0 likes · 13 min read
When and How to Use MySQL Locks: A Deep Dive into Explicit and Implicit Locking
Architecture Digest
Architecture Digest
Dec 6, 2023 · Databases

MySQL Query Optimization and Index Tuning: From Subqueries to Joins

This article analyzes a slow MySQL query that scans millions of rows to find students scoring 100 in Chinese, then demonstrates how adding appropriate single‑column and composite indexes, rewriting the query as a join, and using covering indexes can reduce execution time from hours to milliseconds.

MySQLPerformance TuningQuery Optimization
0 likes · 10 min read
MySQL Query Optimization and Index Tuning: From Subqueries to Joins
dbaplus Community
dbaplus Community
Dec 5, 2023 · Databases

How I Cut an 8‑Second Slow Query to 0.7 Seconds with Two Optimizations

The article walks through a real‑world case of a slow MySQL query that took 8 seconds, explains why simple indexing wasn't enough, and demonstrates two successive rewrites using JOIN‑GROUP BY and NOT IN that reduced execution time to 0.7 seconds while detailing the EXPLAIN analysis.

EXPLAINMySQLPerformance Tuning
0 likes · 6 min read
How I Cut an 8‑Second Slow Query to 0.7 Seconds with Two Optimizations
Programmer DD
Programmer DD
Dec 5, 2023 · Databases

Master the Basics of SQL: Understanding Tables, Keys, and Queries

This article introduces SQL as the standard language for relational databases, explains how data is organized into tables with primary and foreign keys, and walks through essential keywords like SELECT, WHERE, and JOIN to query and relate data effectively.

Foreign KeyJOINRelational Databases
0 likes · 5 min read
Master the Basics of SQL: Understanding Tables, Keys, and Queries
Sanyou's Java Diary
Sanyou's Java Diary
Dec 4, 2023 · Backend Development

When Pagination Breaks: Real‑World Bugs and Practical Fixes

This article recounts three production‑level pagination bugs encountered in a payment system, explains why they occurred—ranging from naive batch processing to MySQL's nondeterministic LIMIT behavior—and shows how proper pagination, ThreadLocal cleanup, and deterministic ordering resolve the issues.

Bug fixingMySQLPagination
0 likes · 16 min read
When Pagination Breaks: Real‑World Bugs and Practical Fixes
DataFunTalk
DataFunTalk
Dec 3, 2023 · Big Data

NetEase Data: Practices and Architecture of a Metrics Middle Platform

This article presents NetEase Data's end‑to‑end experience in building a metrics middle platform, covering product evolution, the motivations for a unified metrics layer, core technologies such as a logical semantic model, a custom metric query language, engine‑agnostic execution, and future roadmap plans.

Data AnalyticsDataOpsMetrics Platform
0 likes · 12 min read
NetEase Data: Practices and Architecture of a Metrics Middle Platform
php Courses
php Courses
Dec 2, 2023 · Databases

Index Optimization Techniques for PHP and MySQL Multi‑Table Queries

Effective index design, including single‑table, foreign‑key, composite, and covering indexes, along with optimizer hints, can dramatically improve the performance of multi‑table queries in PHP‑MySQL applications, and the article provides practical examples and SQL statements for each technique.

Database PerformanceMySQLPHP
0 likes · 4 min read
Index Optimization Techniques for PHP and MySQL Multi‑Table Queries
Java Architect Essentials
Java Architect Essentials
Nov 29, 2023 · Backend Development

Performance Tuning of a Java Backend Service: From 50/s to 500/s Through Profiling, Thread‑Pool, and SQL Optimization

The article details a step‑by‑step investigation and optimization of a Java backend service that initially delivered only 50 requests per second under load, covering profiling, slow‑SQL fixes, thread‑pool tuning, JVM memory adjustments, and Spring bean creation overhead to approach the target 500 req/s.

JavaPerformanceRedis
0 likes · 14 min read
Performance Tuning of a Java Backend Service: From 50/s to 500/s Through Profiling, Thread‑Pool, and SQL Optimization
Top Architect
Top Architect
Nov 28, 2023 · Databases

Performance Comparison of JOIN vs IN in MySQL Queries

This article experimentally compares the performance of JOIN and IN approaches for retrieving order and user data in MySQL, showing that JOIN is faster on small datasets while IN may become costly with large data volumes, and discusses code implementations and practical conclusions.

DatabaseJOINMySQL
0 likes · 10 min read
Performance Comparison of JOIN vs IN in MySQL Queries
Architect
Architect
Nov 27, 2023 · Backend Development

Why 500 req/s Became 50 req/s: A Deep Dive into Spring Bean Creation Bottlenecks

A ToB system that seemed able to handle 500 requests per second stalled at 50 req/s due to hidden lock contention in prototype‑scoped Spring beans, slow SQL updates, excessive logging, and thread‑pool misconfiguration, prompting a step‑by‑step performance investigation and multiple optimizations.

JavaOptimizationPerformance
0 likes · 16 min read
Why 500 req/s Became 50 req/s: A Deep Dive into Spring Bean Creation Bottlenecks