BestHub
Sign in
Tagged articles
2769 articles
Page 16 of 28
Selected Java Interview Questions
Selected Java Interview Questions
Nov 6, 2021 · Databases

Understanding MySQL Indexes: B+Tree Structure, Engine Implementations, and Optimization Techniques

This article explains the fundamentals of MySQL indexes, focusing on B+Tree structures, differences between MyISAM and InnoDB implementations, practical indexing strategies, configuration and SQL tuning tips, and provides a detailed case study with EXPLAIN analysis to help developers design efficient indexes.

B+TreeInnoDBexplain
0 likes · 26 min read
Understanding MySQL Indexes: B+Tree Structure, Engine Implementations, and Optimization Techniques
Aikesheng Open Source Community
Aikesheng Open Source Community
Nov 5, 2021 · Databases

SQLE 1.2111.0-pre1 Release Notes

The SQLE 1.2111.0-pre1 preview release introduces plugin-based support for arbitrary databases, provides a PostgreSQL plugin example, includes API adjustments, fixes a rule‑passing bug, and offers links to the source repository, documentation, and release information for users and administrators.

auditdatabasesplugin
0 likes · 3 min read
SQLE 1.2111.0-pre1 Release Notes
Architecture & Thinking
Architecture & Thinking
Nov 4, 2021 · Databases

Master MySQL: From DDL Basics to Advanced Table Constraints

This guide walks through SQL’s language categories—DDL, DML, DQL, DCL, and TCL—then demonstrates practical database and table management commands such as creating and dropping databases, defining tables with various constraints (not‑null, default, primary/foreign keys, unique, auto‑increment), and modifying or copying fields and tables.

DDLDatabase ManagementTable Constraints
0 likes · 13 min read
Master MySQL: From DDL Basics to Advanced Table Constraints
Top Architect
Top Architect
Nov 3, 2021 · Databases

Understanding SELECT ... FOR UPDATE Locking in MySQL: Row vs. Table Locks

This article explains how MySQL's SELECT ... FOR UPDATE statement adds a pessimistic lock, detailing when it results in row-level locking versus table-level locking based on the presence of indexes or primary keys, and demonstrates the behavior with multiple practical examples.

SELECT FOR UPDATEmysqlrow lock
0 likes · 5 min read
Understanding SELECT ... FOR UPDATE Locking in MySQL: Row vs. Table Locks
Programmer DD
Programmer DD
Nov 3, 2021 · Backend Development

Extending MyBatis‑Plus for ClickHouse: Custom Update, Delete, and Mapper Implementation

This article demonstrates how to extend MyBatis‑Plus to support ClickHouse-specific SQL operations by creating custom enum definitions, method classes, a SQL injector, a super mapper interface, and accompanying unit tests, enabling update, delete, and logical delete functionalities that differ from standard MySQL behavior.

ORMSpring Bootclickhouse
0 likes · 9 min read
Extending MyBatis‑Plus for ClickHouse: Custom Update, Delete, and Mapper Implementation
Aikesheng Open Source Community
Aikesheng Open Source Community
Oct 29, 2021 · Databases

SQLE 1.2110.0-pre1 Release Notes

The pre‑release version 1.2110.0‑pre1 of the open‑source SQL audit tool SQLE is announced, detailing its project overview, repository links, new feature (Online DDL support), UI optimizations, and bug fixes, followed by promotional links and unrelated personal commentary.

SQLEauditopen-source
0 likes · 3 min read
SQLE 1.2110.0-pre1 Release Notes
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Oct 28, 2021 · Databases

MySQL Upgrade Guide: Principles, 8.0 Changes, Pre‑Upgrade Checks, and Step‑by‑Step In‑Place & Logical Migration

This article outlines the principles, recommended practices, and detailed steps for upgrading MySQL from 5.7 to 8.0, covering version compatibility, major 8.0 feature changes, pre‑upgrade checks, in‑place and logical migration procedures, and essential configuration adjustments with example commands.

ConfigurationInnoDBdatabase migration
0 likes · 23 min read
MySQL Upgrade Guide: Principles, 8.0 Changes, Pre‑Upgrade Checks, and Step‑by‑Step In‑Place & Logical Migration
Top Architect
Top Architect
Oct 27, 2021 · Databases

Understanding MySQL InnoDB Deadlocks: Types, Causes, and Prevention Strategies

This article explains MySQL InnoDB lock types, analyzes common deadlock scenarios with detailed SQL examples, describes the underlying locking mechanisms such as next‑key and gap locks, and provides practical prevention and resolution techniques for developers working with transactional databases.

InnoDBconcurrencydatabase
0 likes · 13 min read
Understanding MySQL InnoDB Deadlocks: Types, Causes, and Prevention Strategies
Aikesheng Open Source Community
Aikesheng Open Source Community
Oct 26, 2021 · Databases

Understanding MySQL explicit_defaults_for_timestamp and Its Impact on TIMESTAMP Columns

This article explains how the MySQL system variable explicit_defaults_for_timestamp controls the default and NULL handling of TIMESTAMP columns, demonstrates the differences between OFF and ON settings with practical tests, and discusses why the parameter is being deprecated for stricter time‑data management.

NULLdatabase migrationexplicit_defaults_for_timestamp
0 likes · 10 min read
Understanding MySQL explicit_defaults_for_timestamp and Its Impact on TIMESTAMP Columns
Wukong Talks Architecture
Wukong Talks Architecture
Oct 25, 2021 · Databases

MySQL Index Optimization and Code Review Practices

This article explains MySQL index fundamentals, the B+Tree structure, various index types, the concept of covering indexes to avoid row look‑ups, the left‑most prefix rule, and presents three real‑world optimization cases that illustrate how to design effective composite indexes, reduce index size, and improve query performance while avoiding costly table scans and sorts.

Code reviewComposite IndexDatabase Performance
0 likes · 13 min read
MySQL Index Optimization and Code Review Practices
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Oct 15, 2021 · Backend Development

Comprehensive Guide to MyBatis Batch Insert: Three Methods, Performance Comparison, and Analysis

This article introduces three MyBatis batch insertion techniques—looped single inserts, MyBatis‑Plus batch inserts, and native SQL batch inserts—provides complete implementation code, performance test results for inserting 100,000 records, analyzes the causes of differences, and offers practical solutions to common pitfalls such as MySQL packet size limits.

Batch InsertMyBatisPerformance Test
0 likes · 13 min read
Comprehensive Guide to MyBatis Batch Insert: Three Methods, Performance Comparison, and Analysis
Aikesheng Open Source Community
Aikesheng Open Source Community
Oct 13, 2021 · Databases

MySQL Native Horizontal Sharding with MERGE Tables

This article explains MySQL's native horizontal sharding using MERGE tables, covering the concepts of horizontal versus vertical splitting, table‑level sharding and partitioning, practical examples, advantages, limitations, and suitable use cases for MERGE tables.

MERGE Tabledatabase partitioninghorizontal sharding
0 likes · 11 min read
MySQL Native Horizontal Sharding with MERGE Tables
Su San Talks Tech
Su San Talks Tech
Oct 13, 2021 · Databases

How to Recover Accidentally Deleted MySQL Data Using Binlog

After a client mistakenly imported 60,000 useless rows and a developer’s faulty delete command erased over 100,000 critical records, this guide explains how to use MySQL binlog to locate, extract, and replay the missing SQL statements, restore the data, and prevent future disasters.

BackupBinlogData Recovery
0 likes · 17 min read
How to Recover Accidentally Deleted MySQL Data Using Binlog
ITPUB
ITPUB
Oct 12, 2021 · Databases

How to Handle Pagination After MySQL Sharding: Pitfalls and Solutions

When a MySQL table is sharded into multiple databases or tables, the usual LIMIT offset, pagesize pagination breaks, and this article examines why simple merge fails, then presents three practical approaches—global limit, secondary queries, and jump‑page restriction—highlighting their trade‑offs and limitations.

databasemysqlpagination
0 likes · 13 min read
How to Handle Pagination After MySQL Sharding: Pitfalls and Solutions
Ops Development Stories
Ops Development Stories
Oct 12, 2021 · Databases

Mastering Database Indexes: From Binary Trees to B+Trees and Beyond

This article explains the fundamentals and structures of database indexes—including binary trees, red‑black trees, B‑Tree, B+Tree, hash indexes—and details how MySQL’s InnoDB and MyISAM engines implement clustered and non‑clustered indexes, covering their characteristics, storage files, and query behavior.

B+TreeDatabase IndexesHash Index
0 likes · 9 min read
Mastering Database Indexes: From Binary Trees to B+Trees and Beyond
Big Data Technology & Architecture
Big Data Technology & Architecture
Oct 12, 2021 · Big Data

Data Lake Evolution and a Practical Flink + Iceberg Implementation Guide

This article explores the evolution of data lakes, compares major cloud providers' lake architectures, introduces the emerging lakehouse concept, and provides a step‑by‑step Flink‑Iceberg implementation—including dependencies, catalog setup, table creation, checkpointing, and Kafka ingestion—demonstrating practical big‑data streaming solutions.

Data LakeFlinkIceberg
0 likes · 14 min read
Data Lake Evolution and a Practical Flink + Iceberg Implementation Guide
Java Architect Essentials
Java Architect Essentials
Oct 9, 2021 · Backend Development

Integrating Dataway with Spring Boot: A Step‑by‑Step Tutorial

This article explains how to integrate the Dataway interface‑configuration tool into a Spring Boot project by adding Hasor dependencies, configuring Dataway properties, creating required database tables, setting up the data source, wiring Hasor modules, enabling Hasor in the application, and finally creating and testing a Dataway API without writing any business code.

API ConfigurationDataQLDataway
0 likes · 15 min read
Integrating Dataway with Spring Boot: A Step‑by‑Step Tutorial
Big Data Technology & Architecture
Big Data Technology & Architecture
Oct 9, 2021 · Big Data

Apache Flink 1.7–1.14 Release Highlights and Feature Evolution

This article provides a comprehensive overview of Apache Flink's major releases from version 1.7 to 1.14, detailing new APIs, state management improvements, Kubernetes integration, SQL and Table API enhancements, checkpointing advances, and performance optimizations that together illustrate the platform's evolution for both streaming and batch processing workloads.

Apache FlinkBatch ProcessingCheckpoint
0 likes · 78 min read
Apache Flink 1.7–1.14 Release Highlights and Feature Evolution
macrozheng
macrozheng
Oct 8, 2021 · Databases

How to Speed Up MySQL Deep Pagination: 4 Proven Optimization Techniques

This article explains why MySQL LIMIT deep pagination becomes slow with large offsets and presents four practical optimization methods—including subqueries, delayed INNER JOIN, tag‑recording, and BETWEEN…AND—demonstrated with real‑world production examples.

mysqlpaginationquery optimization
0 likes · 11 min read
How to Speed Up MySQL Deep Pagination: 4 Proven Optimization Techniques
21CTO
21CTO
Oct 6, 2021 · Databases

Master MySQL 8.0 JSON Functions: Practical Tips and Code Samples

This article introduces MySQL 8.0's enhanced JSON capabilities, covering key constraints, storage functions, GeoJSON support, indexing, in‑place updates, essential JSON utilities, path expressions, extraction, modification techniques, and the powerful JSON_TABLE feature with clear code examples.

BackendData TypesJSON
0 likes · 7 min read
Master MySQL 8.0 JSON Functions: Practical Tips and Code Samples
21CTO
21CTO
Oct 4, 2021 · Databases

October 2023 DB‑Engines Ranking: Top 10 Databases & Emerging Trends

The October DB‑Engines popularity ranking shows the same top‑10 databases as September, highlights score gains for MySQL and PostgreSQL, notes a year‑over‑year decline for the three leading systems, and reveals Snowflake’s rise into the top‑20, all based on five key popularity indicators.

DB-EnginesNoSQLdatabases
0 likes · 4 min read
October 2023 DB‑Engines Ranking: Top 10 Databases & Emerging Trends
IT Architects Alliance
IT Architects Alliance
Oct 4, 2021 · Databases

Understanding MySQL Indexes: Types, Creation, and Optimization

This article explains MySQL indexes, covering their definition, benefits, various types such as B‑tree and B+‑tree, practical techniques for creating high‑performance indexes like prefix, composite, and clustering indexes, and how to inspect and maintain index information and fragmentation.

B+Treeindexmysql
0 likes · 17 min read
Understanding MySQL Indexes: Types, Creation, and Optimization
Java Captain
Java Captain
Oct 2, 2021 · Databases

MySQL Binlog Data Recovery After Accidental Bulk Deletion: Case Study and Best Practices

This article recounts a real-world incident where a client mistakenly imported 60,000 rows of erroneous Excel data into a MySQL production database, leading to an accidental bulk delete, and explains how the team used MySQL binlog to recover the lost data while offering practical safeguards to prevent similar disasters.

BinlogData RecoveryDatabase Backup
0 likes · 17 min read
MySQL Binlog Data Recovery After Accidental Bulk Deletion: Case Study and Best Practices
Aikesheng Open Source Community
Aikesheng Open Source Community
Sep 30, 2021 · Databases

Modifying Trusted IP Whitelist for MySQL Users

This article explains how MySQL implements trusted IP access control via user@host definitions, demonstrates creating and updating user accounts and associated metadata tables, and provides step‑by‑step procedures—including DCL commands, metadata updates, and handling of stored objects—to safely modify trusted IPs in production environments.

Database AdministrationTrusted IPUser Management
0 likes · 20 min read
Modifying Trusted IP Whitelist for MySQL Users
StarRocks
StarRocks
Sep 30, 2021 · Databases

Master StarRocks Lateral Join & Unnest for Efficient Row‑to‑Column Transformations

StarRocks 1.18 introduces Lateral Join + Unnest for elegant row‑to‑multiple‑row conversion, Fast Decimal with up to 38‑digit precision and 4× faster arithmetic, extensive Bitmap function enhancements, and a suite of import, storage, operator, and ecosystem optimizations that dramatically boost query performance and scalability.

Bitmap OptimizationFast DecimalLATERAL JOIN
0 likes · 7 min read
Master StarRocks Lateral Join & Unnest for Efficient Row‑to‑Column Transformations
Java Backend Technology
Java Backend Technology
Sep 30, 2021 · Databases

Why MySQL Picks Full Table Scan Over Index with ORDER BY id LIMIT 1

The article examines a MySQL optimizer bug where a query with a WHERE clause on uid, ORDER BY id ASC, and LIMIT 1 incorrectly triggers a full table scan despite a usable composite index, explains the optimizer’s cost calculations, and offers workarounds such as FORCE INDEX or a harmless arithmetic trick to force index usage.

Full Table Scanindexmysql
0 likes · 8 min read
Why MySQL Picks Full Table Scan Over Index with ORDER BY id LIMIT 1
ITPUB
ITPUB
Sep 29, 2021 · Databases

INSERT vs LOAD DATA INFILE in MySQL: When to Choose Each for Speed and Bulk Loads

This article compares MySQL's INSERT INTO and LOAD DATA INFILE statements, explains their syntax, shows practical examples, highlights when each should be used for bulk data loading, discusses error handling with IGNORE, and explains why LOAD DATA INFILE is typically faster.

InsertLOAD DATA INFILEdata import
0 likes · 7 min read
INSERT vs LOAD DATA INFILE in MySQL: When to Choose Each for Speed and Bulk Loads
Aikesheng Open Source Community
Aikesheng Open Source Community
Sep 29, 2021 · Databases

Using MySQL 8.0 JSON Schema Validation Functions

This article explains how MySQL 8.0 introduces strict JSON schema validation, demonstrates the json_schema_valid and json_schema_validation_report functions with array and object examples, and shows how to enforce schema checks in tables using CHECK constraints.

JSON Schemadatabasejson_schema_valid
0 likes · 11 min read
Using MySQL 8.0 JSON Schema Validation Functions
Baidu Intelligent Testing
Baidu Intelligent Testing
Sep 28, 2021 · Databases

Design and Evolution of BaikalDB: A Cloud‑Native Distributed Database for Commercial Advertising Systems

This article examines the business storage requirements of large‑scale advertising platforms and details how BaikalDB was architected as a cloud‑native, MySQL‑compatible distributed database that combines OLTP, OLAP, KV and full‑text capabilities while ensuring high reliability, low cost and linear scalability.

AdvertisingBaikalDBCloud Native
0 likes · 24 min read
Design and Evolution of BaikalDB: A Cloud‑Native Distributed Database for Commercial Advertising Systems
Big Data Technology Architecture
Big Data Technology Architecture
Sep 28, 2021 · Big Data

Integrating Apache Kyuubi with CDH 6 and Spark 3: Deployment, Configuration, and Performance Tuning

This guide explains how to deploy Apache Kyuubi on a CDH 6 cluster, replace HiveServer2 with Kyuubi, integrate Spark 3, apply necessary patches, configure environment and Spark settings, and optimize engine sharing for various workloads, providing complete code snippets and step‑by‑step instructions.

CDHHiveServer2Kyuubi
0 likes · 19 min read
Integrating Apache Kyuubi with CDH 6 and Spark 3: Deployment, Configuration, and Performance Tuning
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Sep 27, 2021 · Backend Development

Implementing Batch Insert with MyBatis-Plus in Java

This article explains how to improve database insertion performance in Java by replacing per‑iteration inserts with MyBatis‑Plus’s saveBatch method, detailing dependency setup, schema creation, entity, controller, service, and mapper code for efficient bulk operations.

BackendBatch InsertSpring Boot
0 likes · 8 min read
Implementing Batch Insert with MyBatis-Plus in Java
Code Ape Tech Column
Code Ape Tech Column
Sep 26, 2021 · Databases

MySQL Index Optimization: Fundamentals, Types, and Practical Cases

This article explains MySQL index fundamentals, B+‑tree implementation, the left‑most prefix rule, back‑to‑table issues, and provides three practical optimization cases with code examples to help developers design efficient composite indexes and avoid performance pitfalls.

Index Optimizationdatabasesql
0 likes · 15 min read
MySQL Index Optimization: Fundamentals, Types, and Practical Cases
ITPUB
ITPUB
Sep 26, 2021 · Databases

Master SQL Basics: From Zero to Simple Queries with Real Examples

This tutorial walks beginners through the fundamentals of SQL, explaining what it is, how to run simple SELECT statements, create tables, insert, update, delete records, use WHERE clauses, and even generate fun graphics like stars and calendars using advanced queries.

CRUDData TypesDatabase Basics
0 likes · 11 min read
Master SQL Basics: From Zero to Simple Queries with Real Examples
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Sep 26, 2021 · Databases

MySQL Index Optimization: Principles, Types, and Practical Case Studies

This article explains MySQL index fundamentals, different index structures, the concept of covering indexes and the left‑most prefix rule, and presents three real‑world optimization cases that illustrate how to design effective composite and partial indexes to avoid table scans and improve query performance.

Database designIndex OptimizationQuery Performance
0 likes · 14 min read
MySQL Index Optimization: Principles, Types, and Practical Case Studies
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Sep 26, 2021 · Databases

Why MySQL Optimizer Chooses a Full Table Scan for ORDER BY id ASC LIMIT 1 and How to Force the Correct Index

The article analyzes a MySQL optimizer bug where a query with ORDER BY id ASC LIMIT 1 triggers a full‑table scan despite an applicable idx_uid_stat index, explains the cost‑based decision process, and presents two practical work‑arounds—using FORCE INDEX or a harmless arithmetic expression—to ensure the index is used.

Full Table Scanmysqloptimizer
0 likes · 7 min read
Why MySQL Optimizer Chooses a Full Table Scan for ORDER BY id ASC LIMIT 1 and How to Force the Correct Index
转转QA
转转QA
Sep 26, 2021 · Big Data

A/B Testing Process Improvement and Validation Guide

This article outlines a comprehensive A/B testing workflow, covering historical issues, business test process improvements, detailed implementation steps, SQL validation scripts, data verification in analytics platforms, and practical notes to ensure accurate experiment data collection and analysis.

A/B testingBig Datadata validation
0 likes · 10 min read
A/B Testing Process Improvement and Validation Guide
NetEase Smart Enterprise Tech+
NetEase Smart Enterprise Tech+
Sep 26, 2021 · Databases

How ClickHouse Powers a Billion‑User Profiling Platform at Sub‑5‑Second Latency

This article shares NetEase’s experience building a user‑profile platform with ClickHouse, detailing the business background, challenges of massive data and complex queries, core table designs, data ingestion, bitmap techniques, performance gains, and future plans for scaling and optimization.

Bitmap IndexReal-time analyticsclickhouse
0 likes · 13 min read
How ClickHouse Powers a Billion‑User Profiling Platform at Sub‑5‑Second Latency
ZhiKe AI
ZhiKe AI
Sep 24, 2021 · Databases

How to Manually Re‑Add a Detached MySQL MGR Cluster Node

This guide walks through exporting business databases, re‑initializing the MySQL instance, importing data, extracting GTID information, creating replication and monitoring accounts with helper functions, resetting logs, and finally re‑joining the node to a MySQL Group Replication cluster.

Database RecoveryGTIDGroup Replication
0 likes · 8 min read
How to Manually Re‑Add a Detached MySQL MGR Cluster Node
Laravel Tech Community
Laravel Tech Community
Sep 23, 2021 · Databases

Common MySQL Commands and Basic Database/Table Operations

This article presents a concise guide to the most frequently used MySQL commands, covering how to list databases and tables, create and drop databases and tables, and perform essential CRUD operations such as inserting, querying, updating, and deleting records.

CRUDTable OperationsTutorial
0 likes · 5 min read
Common MySQL Commands and Basic Database/Table Operations
Programmer DD
Programmer DD
Sep 22, 2021 · Databases

Master MySQL 8.0 JSON Functions: Practical Tips and Code Samples

This article summarizes the most useful MySQL 8.0 JSON features—including storage limits, indexing, in‑place updates, path expressions, merging, and table functions—providing clear code examples and guidance for developers who need to work with JSON data in MySQL.

JSONJSON FunctionsMySQL8
0 likes · 8 min read
Master MySQL 8.0 JSON Functions: Practical Tips and Code Samples
NetEase Game Operations Platform
NetEase Game Operations Platform
Sep 18, 2021 · Big Data

StreamflySQL: NetEase Games’ Journey from Template JAR to SQL Gateway for Flink SQL Platformization

This article details NetEase Games’ evolution of its Flink SQL platform, from the early StreamflySQL v1 template‑JAR approach to the v2 SQL‑Gateway architecture, discussing design decisions, challenges such as metadata persistence, multi‑tenant security, horizontal scaling, and job state management.

FlinkReal-time analyticsplatform engineering
0 likes · 17 min read
StreamflySQL: NetEase Games’ Journey from Template JAR to SQL Gateway for Flink SQL Platformization
Selected Java Interview Questions
Selected Java Interview Questions
Sep 15, 2021 · Big Data

Performance and Feature Comparison between Elasticsearch and ClickHouse for Log Analytics

This article compares Elasticsearch and ClickHouse in terms of architecture, query capabilities, and performance for log analytics, presenting test setups, Docker‑compose configurations, query examples, and benchmark results that show ClickHouse generally outperforms Elasticsearch in most basic query scenarios.

ElasticsearchLog Analyticsclickhouse
0 likes · 12 min read
Performance and Feature Comparison between Elasticsearch and ClickHouse for Log Analytics
Python Crawling & Data Mining
Python Crawling & Data Mining
Sep 12, 2021 · Databases

How ClickHouse Projections Supercharge Query Performance

The article explains ClickHouse's new Projection feature, how it overcomes MergeTree's single‑sort limitation and materialized view drawbacks, provides step‑by‑step commands to create, materialize, and query projections, demonstrates massive performance gains, and outlines the rules for automatic projection selection.

Database OptimizationProjectionclickhouse
0 likes · 12 min read
How ClickHouse Projections Supercharge Query Performance
Big Data Technology & Architecture
Big Data Technology & Architecture
Sep 11, 2021 · Big Data

Deep Dive into Flink Table & SQL Window Functions, UDFs, and Hive Integration

This article provides a comprehensive guide to Flink Table and SQL window semantics—including group, tumbling, sliding, and session windows—covers over windows, demonstrates how to define windows in SQL, explains built‑in functions, shows how to implement scalar, table, aggregate and table‑aggregate UDFs, and details Flink's integration with Hive, complete with Maven dependencies and runnable examples.

FlinkHive IntegrationTable API
0 likes · 27 min read
Deep Dive into Flink Table & SQL Window Functions, UDFs, and Hive Integration
Laravel Tech Community
Laravel Tech Community
Sep 10, 2021 · Databases

How to Remove Duplicate Records in MySQL Tables

This article explains why duplicate rows appeared in production MySQL tables, demonstrates how to identify them with SELECT queries, and provides two SQL solutions—one to delete all duplicates and another to keep a single record per duplicated key—while preserving data integrity.

data deduplicationdatabase cleanupduplicate removal
0 likes · 5 min read
How to Remove Duplicate Records in MySQL Tables
Open Source Tech Hub
Open Source Tech Hub
Sep 10, 2021 · Databases

How LEFT JOIN Works with WHERE: When to Filter in ON vs WHERE

This guide explains how LEFT JOIN creates a temporary result set, compares the effects of applying a WHERE filter after the join versus embedding the condition in the ON clause, and shows practical SQL examples with sample tables and result analysis.

LEFT JOINON clauseWHERE clause
0 likes · 5 min read
How LEFT JOIN Works with WHERE: When to Filter in ON vs WHERE
Big Data Technology & Architecture
Big Data Technology & Architecture
Sep 10, 2021 · Big Data

Understanding Flink Table API and SQL: Dependencies, Planners, and Practical Usage

This article provides a comprehensive guide to Apache Flink's Table API and SQL, covering required dependencies, the differences between old and Blink planners, program structure, table environment creation, catalog registration, query execution, conversion between DataStream and Table, update modes, and time attribute handling, with Scala code examples throughout.

FlinkScalaStreaming
0 likes · 26 min read
Understanding Flink Table API and SQL: Dependencies, Planners, and Practical Usage
Architecture Digest
Architecture Digest
Sep 8, 2021 · Databases

Why Optimize Slow SQL and Practical MySQL Performance Tuning Techniques

This article explains the impact of slow SQL on database resources and user experience, outlines priority rules for addressing slow queries, details MySQL execution steps, identifies key performance factors, and provides concrete optimization methods including enabling slow‑query logs, indexing, I/O merging, and distributed architecture.

Database Optimizationmysqlperformance
0 likes · 17 min read
Why Optimize Slow SQL and Practical MySQL Performance Tuning Techniques
Qunar Tech Salon
Qunar Tech Salon
Sep 6, 2021 · Databases

Comparison of Sequence Usage Across Oracle, PostgreSQL, and MySQL

This article examines how Oracle, PostgreSQL, and MySQL implement and use database sequences for primary keys, covering explicit calls, trigger‑based, DEFAULT, and AUTO_INCREMENT methods, version support, and the effects of INSERT, UPDATE, DELETE, and TRUNCATE operations, concluding with a comparative summary.

OracleSequencemysql
0 likes · 30 min read
Comparison of Sequence Usage Across Oracle, PostgreSQL, and MySQL
Architects Research Society
Architects Research Society
Sep 4, 2021 · Databases

Why Data Scientists Should Learn PostgreSQL

This article explains why mastering SQL and PostgreSQL is essential for data scientists, outlines the core skills of the role, describes PostgreSQL’s features, lists its advantages and drawbacks for data science, and suggests resources for getting started.

Big DataData ScienceHTAP
0 likes · 10 min read
Why Data Scientists Should Learn PostgreSQL
Xiaolei Talks DB
Xiaolei Talks DB
Sep 4, 2021 · Databases

Mastering TiDB Performance: Layered and Scenario‑Based Optimization Strategies

This article explores TiDB performance optimization by examining layered approaches—hardware, software, and SQL—and scenario‑specific tactics such as read/write hotspot handling, OLAP challenges, and distributed transaction tuning, offering practical insights and real‑world case studies from industry experts.

Database TuningHardwareTiDB
0 likes · 7 min read
Mastering TiDB Performance: Layered and Scenario‑Based Optimization Strategies
High Availability Architecture
High Availability Architecture
Sep 3, 2021 · Backend Development

MyBatis Complete Example and Internal Architecture Overview

This article provides a thorough introduction to MyBatis, including a complete beginner example with database schema, Maven configuration, XML and Java mapper files, and a demo program, followed by an in‑depth explanation of MyBatis’s lifecycle, core components such as SqlSession, Executor, StatementHandler, ParameterHandler, ResultSetHandler, and their interactions.

ExecutorMyBatisORM
0 likes · 27 min read
MyBatis Complete Example and Internal Architecture Overview
vivo Internet Technology
vivo Internet Technology
Sep 2, 2021 · Backend Development

Complete MyBatis Example and Architecture Overview

The article presents a step‑by‑step MyBatis tutorial that creates a sample user table, adds Maven dependencies, configures MyBatis, defines mapper XML and Java interfaces, demonstrates a test program, and explains core components such as SqlSession, Executor, StatementHandler, ParameterHandler, and ResultSetHandler.

ExecutorMyBatisORM
0 likes · 28 min read
Complete MyBatis Example and Architecture Overview
Tencent Cloud Developer
Tencent Cloud Developer
Sep 2, 2021 · Databases

Understanding Geohash: Principles, Implementation, and Applications

Geohash encodes latitude‑longitude pairs into short base‑32 strings by recursively bisecting coordinate ranges and interleaving bits, allowing fast proximity queries via prefix matching, with precision controlled by string length, and is supported natively in Redis and useful for location‑based services.

GeoHashPHPSpatial Indexing
0 likes · 12 min read
Understanding Geohash: Principles, Implementation, and Applications
Wukong Talks Architecture
Wukong Talks Architecture
Sep 1, 2021 · Databases

Understanding MySQL EXPLAIN Output: Columns and Their Meaning

This article explains the purpose and interpretation of each column in MySQL's EXPLAIN output, covering identifiers, select types, table sources, partition info, access types, possible keys, actual keys, key lengths, row estimates, filtering percentages, and extra execution details, with visual examples and code snippets.

Query Executionexplainindexes
0 likes · 10 min read
Understanding MySQL EXPLAIN Output: Columns and Their Meaning
ByteDance ADFE Team
ByteDance ADFE Team
Aug 31, 2021 · Big Data

Evolution of the Big Data Technology Stack Over the Past Five Years

This article reviews the evolution of big data technologies in the last five years, covering streaming and batch processing frameworks, column‑store NoSQL databases, programming language trends, the cloud‑native multi‑model database Lindorm, and practical Flink/Blink usage with code examples.

Big DataFlinkLindorm
0 likes · 24 min read
Evolution of the Big Data Technology Stack Over the Past Five Years
Alibaba Cloud Developer
Alibaba Cloud Developer
Aug 30, 2021 · Databases

Master SQL: Discover the 6 Core Language Components in One Course

This article introduces the six fundamental parts of Structured Query Language (SQL)—DQL, DML, TPL, DCL, DDL, and CCL—while promoting a comprehensive Alibaba Cloud developer course that covers each component with detailed lessons and practical examples.

Data Manipulation LanguageData Query LanguageSQL Course
0 likes · 4 min read
Master SQL: Discover the 6 Core Language Components in One Course
Selected Java Interview Questions
Selected Java Interview Questions
Aug 30, 2021 · Databases

MySQL Interview Questions and Answers: Indexes, InnoDB vs MyISAM, Transactions, Optimization, and Design

This article compiles a comprehensive set of MySQL interview questions covering index types, the differences between MyISAM and InnoDB, the rationale for auto‑increment primary keys, sharding strategies, ACID properties, isolation levels, storage‑engine trade‑offs, normalization, index best practices, data types, performance tuning, locking mechanisms, B+Tree characteristics, and common SQL operations.

Database designInnoDBTransactions
0 likes · 28 min read
MySQL Interview Questions and Answers: Indexes, InnoDB vs MyISAM, Transactions, Optimization, and Design
Top Architect
Top Architect
Aug 26, 2021 · Databases

Understanding MySQL Locks: Table, Row, and Page Locking Mechanisms

This article explains why MySQL uses locks, describes table‑level, row‑level, and page‑level locking, outlines lock types such as shared, exclusive, and intention locks, and provides practical usage examples and common troubleshooting tips for InnoDB and other storage engines.

InnoDBLocksconcurrency
0 likes · 7 min read
Understanding MySQL Locks: Table, Row, and Page Locking Mechanisms
FunTester
FunTester
Aug 26, 2021 · Databases

Master MySQL Interview Questions: 33 Essential Queries and Answers

This article presents a complete MySQL interview guide, including a script to create and populate tables for students, teachers, courses, scores, and grades, followed by 33 common interview questions with detailed SQL solutions covering selection, aggregation, joins, subqueries, and ordering.

Queriesdata importdatabase
0 likes · 19 min read
Master MySQL Interview Questions: 33 Essential Queries and Answers
Selected Java Interview Questions
Selected Java Interview Questions
Aug 25, 2021 · Databases

ClickHouse Overview: Architecture, MySQL Migration, Performance Testing, and Practical Tips

This article introduces ClickHouse, a high‑performance open‑source columnar database, explains its architecture versus row‑based systems, details migration from MySQL, showcases installation, performance benchmarks, data‑sync strategies, common pitfalls, and summarizes its benefits for large‑scale analytical workloads.

Big DataColumnar DatabaseData Migration
0 likes · 7 min read
ClickHouse Overview: Architecture, MySQL Migration, Performance Testing, and Practical Tips
Programmer DD
Programmer DD
Aug 25, 2021 · Databases

How to Efficiently Insert Massive Data Without Duplicates in MySQL

This article explains several MySQL techniques—INSERT IGNORE, ON DUPLICATE KEY UPDATE, INSERT…SELECT WHERE NOT EXISTS, and REPLACE—plus a practical MyBatis batch‑insert example, to handle large‑scale data imports while preventing duplicate records.

Batch InsertMyBatisduplicate handling
0 likes · 5 min read
How to Efficiently Insert Massive Data Without Duplicates in MySQL
Programmer DD
Programmer DD
Aug 22, 2021 · Databases

How ClickHouse Boosted Query Speed 200×: A Practical Migration Guide

This article introduces ClickHouse as a column‑oriented OLAP database, compares it with traditional row‑based databases, and details a real‑world migration from MySQL that reduced query time from minutes to under one second, along with performance testing, sync strategies, and common pitfalls.

Columnar DatabaseData Migrationclickhouse
0 likes · 7 min read
How ClickHouse Boosted Query Speed 200×: A Practical Migration Guide
Top Architect
Top Architect
Aug 22, 2021 · Databases

Why Using Stored Procedures for Simple Existence Checks Can Be Problematic

The article examines a real‑world scenario where a developer tried to reuse existing stored procedures to merely check the presence of Job, Certification, and Disclosure records, discusses the pitfalls of such an approach, and explains why storing this logic in T‑SQL is often fragile and hard to maintain.

Stored Procedurescode-reusedatabase
0 likes · 6 min read
Why Using Stored Procedures for Simple Existence Checks Can Be Problematic
Architects' Tech Alliance
Architects' Tech Alliance
Aug 21, 2021 · Databases

In-Memory Databases: Concepts, Evolution, Applications, and Selection Guide

This whitepaper explains the concept of in‑memory databases, traces their historical development, outlines core attributes and typical use cases in e‑commerce, live streaming and telecom, compares leading products, and provides technical and management recommendations for hardware and product selection as well as future trends.

In-Memory DatabaseKey-ValuePersistent Memory
0 likes · 14 min read
In-Memory Databases: Concepts, Evolution, Applications, and Selection Guide
Top Architect
Top Architect
Aug 20, 2021 · Databases

Querying Multi‑Business Unit Product Sales Statistics with MySQL and MyBatis Dynamic SQL

This article explains how to retrieve sales statistics for multiple business units and their associated products from a MySQL table, compares several implementation approaches—including loop queries, OR concatenation, mixed filtering, and row‑comparison using MyBatis dynamic SQL—evaluates index usage, and provides the final recommended solution.

Database QueryDynamic SQLMyBatis
0 likes · 8 min read
Querying Multi‑Business Unit Product Sales Statistics with MySQL and MyBatis Dynamic SQL
FunTester
FunTester
Aug 20, 2021 · Databases

Why Is One MySQL CPU Core at 99%? A Step‑by‑Step Troubleshooting Guide

During a performance test a MySQL server showed one CPU core constantly at 99% while the others were idle, prompting a detailed investigation that checks I/O thread settings, multi‑core utilization, transaction locks, slow‑query logging, and index optimization to resolve the bottleneck.

Database OptimizationInnoDBSlow Query Log
0 likes · 6 min read
Why Is One MySQL CPU Core at 99%? A Step‑by‑Step Troubleshooting Guide
ITPUB
ITPUB
Aug 18, 2021 · Databases

Master SQL Basics: From Core Concepts to Advanced Queries and Database Management

This comprehensive guide covers fundamental SQL concepts, syntax, and terminology, then walks through CRUD operations, subqueries, joins, unions, functions, ordering, grouping, data definition, transaction control, permission management, stored procedures, cursors, and triggers, providing clear examples for each.

CRUDJoinsStored Procedures
0 likes · 28 min read
Master SQL Basics: From Core Concepts to Advanced Queries and Database Management
Aikesheng Open Source Community
Aikesheng Open Source Community
Aug 18, 2021 · Databases

Anti‑Normalization in MySQL: Reducing Joins with Redundant Columns

The article explains the drawbacks of strict relational normalization, introduces the concept of anti‑normalization (controlled redundancy) to simplify queries, demonstrates it with a set of employee, department, salary tables and four typical query scenarios, and shows how denormalizing the schema can dramatically improve MySQL query performance.

Anti-NormalizationDatabase designDenormalization
0 likes · 11 min read
Anti‑Normalization in MySQL: Reducing Joins with Redundant Columns
IT Xianyu
IT Xianyu
Aug 17, 2021 · Databases

Key New Features of MySQL 8.0 for Relational Databases

MySQL 8.0 introduces several relational‑database enhancements, including invisible indexes for performance tuning, persistent configuration via SET PERSIST, default utf8mb4 character set, support for Common Table Expressions, and window functions, each illustrated with practical SQL examples.

8.0CTEdatabase
0 likes · 7 min read
Key New Features of MySQL 8.0 for Relational Databases
Java Captain
Java Captain
Aug 15, 2021 · Databases

Querying Multi‑Business Unit Sales Statistics Using Row Comparison in MySQL

The article describes how to design a MySQL table for product sales statistics, initialize large data sets, and compare several approaches—including loop queries, OR concatenation, mixed filtering, and row‑comparison techniques—ultimately selecting row‑comparison as the most efficient solution within MyBatis dynamic SQL constraints.

Database designDynamic SQLMyBatis
0 likes · 6 min read
Querying Multi‑Business Unit Sales Statistics Using Row Comparison in MySQL
IT Architects Alliance
IT Architects Alliance
Aug 14, 2021 · Big Data

An Introduction to Dimensional Modeling in Data Warehousing

This article provides a comprehensive overview of data warehouse concepts, compares classic warehouse models, explains dimensional modeling fundamentals such as fact and dimension tables, demonstrates a practical e‑commerce scenario with schema design and SQL query examples, and discusses real‑world trade‑offs.

Big DataETLStar Schema
0 likes · 9 min read
An Introduction to Dimensional Modeling in Data Warehousing
ITPUB
ITPUB
Aug 13, 2021 · Databases

Why LIMIT with Large OFFSET Slows MySQL and How to Speed It Up

When a MySQL query uses LIMIT with a large offset on a table of millions of rows, the database must scan hundreds of thousands of index entries and corresponding clustered rows, causing massive random I/O; rewriting the query with a sub‑query join reduces I/O dramatically, cutting execution time from over a minute to under a second while also preventing buffer‑pool pollution.

InnoDBLIMITbuffer pool
0 likes · 9 min read
Why LIMIT with Large OFFSET Slows MySQL and How to Speed It Up
Top Architect
Top Architect
Aug 13, 2021 · Backend Development

Implementing Student Score Statistics with Fluent MyBatis, MyBatis, and MyBatis‑Plus

This article demonstrates how to use Fluent MyBatis, native MyBatis, and MyBatis‑Plus to query a student_score table for term‑wise statistics of English, Math, and Chinese scores, providing complete code examples, SQL statements, mapper definitions, and code‑generation configurations for each approach.

Fluent MyBatisMyBatisbackend-development
0 likes · 9 min read
Implementing Student Score Statistics with Fluent MyBatis, MyBatis, and MyBatis‑Plus
Liangxu Linux
Liangxu Linux
Aug 10, 2021 · Databases

How to Efficiently Remove Duplicate Rows in MySQL Tables

This guide explains step‑by‑step how to identify and delete duplicate records in MySQL tables, covering simple SELECT checks, handling MySQL’s update‑from limitation, and fast deletion techniques that keep one record per duplicate group.

DELETEGROUP BYduplicate removal
0 likes · 5 min read
How to Efficiently Remove Duplicate Rows in MySQL Tables
Java Backend Technology
Java Backend Technology
Aug 10, 2021 · Databases

How to Efficiently Remove Duplicate Rows in MySQL Tables

This article explains why a naïve Python script for deleting duplicate MySQL rows is too slow, demonstrates the MySQL error caused by deleting from the same table you query, and provides two pure‑SQL solutions: one that removes all duplicates and another that keeps a single row per duplicate key.

data deduplicationdatabase cleanupduplicate removal
0 likes · 5 min read
How to Efficiently Remove Duplicate Rows in MySQL Tables
Programmer DD
Programmer DD
Aug 7, 2021 · Databases

Why MySQL NULL Can Still Use Indexes and How It Affects Query Performance

This article explains how MySQL treats NULL values, the operators and functions for handling them, demonstrates that IS NULL can still use indexes, shows the impact on aggregate functions, distinct, group by and order by, and recommends defining columns NOT NULL to avoid performance pitfalls.

NULLindexsql
0 likes · 15 min read
Why MySQL NULL Can Still Use Indexes and How It Affects Query Performance
High Availability Architecture
High Availability Architecture
Aug 6, 2021 · Databases

Design and Evolution of BaikalDB: A Distributed Database for Commercial Product Systems

This article examines the requirements of commercial advertising systems for data storage, traces the evolution from single‑node MySQL to BaikalDB’s cloud‑native, MySQL‑compatible distributed architecture, and details its storage, compute, and scheduling designs, highlighting key features such as Raft replication, RocksDB storage, and hybrid OLTP/OLAP support.

BaikalDBRocksDBStorage Architecture
0 likes · 25 min read
Design and Evolution of BaikalDB: A Distributed Database for Commercial Product Systems
ITPUB
ITPUB
Aug 5, 2021 · Databases

How PolarDB‑X’s SQL Flashback Restores Accidentally Deleted Rows in Seconds

This article explains how PolarDB‑X classifies different data‑deletion scenarios, compares traditional recovery methods like PITR, Flashback Query, and binlog‑based tools, and introduces its precise SQL‑level flashback feature that uses TraceID to quickly and accurately restore mistakenly deleted rows.

BinlogData RecoveryFlashback
0 likes · 13 min read
How PolarDB‑X’s SQL Flashback Restores Accidentally Deleted Rows in Seconds