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2820 articles · Page 24 of 29
Aikesheng Open Source Community
Aikesheng Open Source Community
Oct 14, 2019 · Databases

Analyzing MySQL InnoDB Thread Concurrency Issues and Their Resolution

This article examines a MySQL performance problem where frequent requests become unresponsive, analyzes processlist, system I/O/CPU metrics, and pstack traces to identify InnoDB thread concurrency and concurrency tickets as the root cause, then explains the relevant parameters, configuration guidelines, and a simulated test to demonstrate the solution.

InnoDBMySQLSQL
0 likes · 25 min read
Analyzing MySQL InnoDB Thread Concurrency Issues and Their Resolution
Programmer DD
Programmer DD
Oct 11, 2019 · Databases

Understanding MySQL Transaction Isolation Levels: ACID, Tests, and Practical Guide

This article explains the concept of database transactions, the ACID properties, details MySQL’s four isolation levels—Read Uncommitted, Read Committed, Repeatable Read, and Serializable—and provides step‑by‑step command‑line experiments demonstrating phenomena such as dirty reads, non‑repeatable reads, phantom reads, and serialization effects.

ACIDMySQLSQL
0 likes · 9 min read
Understanding MySQL Transaction Isolation Levels: ACID, Tests, and Practical Guide
Aikesheng Open Source Community
Aikesheng Open Source Community
Oct 9, 2019 · Databases

Guide to MySQL InnoDB Tablespace Encryption: Overview, Configuration, Key Management, Import/Export, Backup and Restore

This article provides a comprehensive guide to MySQL InnoDB tablespace encryption, covering its architecture, supported plugins, configuration steps, key rotation, limitations, encrypted table operations, import/export procedures, and backup/restore methods using mysqlbackup and innobackupex.

InnoDBMySQLSQL
0 likes · 17 min read
Guide to MySQL InnoDB Tablespace Encryption: Overview, Configuration, Key Management, Import/Export, Backup and Restore
HomeTech
HomeTech
Oct 9, 2019 · Big Data

Design and Implementation of a Flink‑Based Real‑Time Data Platform at Autohome

This article describes how Autohome migrated its real‑time analytics from Storm to a Flink‑SQL platform, detailing the architectural design, development and operational advantages, practical use cases such as recommendation metrics, and future plans for ecosystem expansion and open‑source release.

Data WarehouseFlinkReal-time Streaming
0 likes · 12 min read
Design and Implementation of a Flink‑Based Real‑Time Data Platform at Autohome
Big Data Technology & Architecture
Big Data Technology & Architecture
Oct 3, 2019 · Big Data

Data Development Interview Tips and Career Guidance

This article offers practical advice for data development job interviews, explaining why Java is essential, comparing Java and Python, outlining required backend framework knowledge, discussing the role of SQL and data warehousing, and addressing work‑life concerns such as overtime and company size choices.

Big DataCareer AdviceData Engineering
0 likes · 4 min read
Data Development Interview Tips and Career Guidance
NetEase Game Operations Platform
NetEase Game Operations Platform
Sep 28, 2019 · Databases

Introducing mycli: A Feature‑Rich MySQL Command‑Line Client

This article introduces mycli, a Python‑based MySQL command‑line client that offers easy installation via pip, advanced auto‑completion, high‑risk operation confirmations, customizable syntax highlighting, output paging, command bookmarking, logging, multiline editing, flexible credential handling, and additional features such as SSL support and query looping.

Database ToolsMyCLIMySQL
0 likes · 9 min read
Introducing mycli: A Feature‑Rich MySQL Command‑Line Client
Xueersi Online School Tech Team
Xueersi Online School Tech Team
Sep 27, 2019 · Big Data

Design Principles and Architecture of Apache Kylin for Sub‑Second OLAP Queries

This article explains how Apache Kylin, an open‑source distributed analytics engine built on Hadoop/Spark, achieves sub‑second OLAP query performance through pre‑computed cubes, a layered cuboid generation algorithm, bitmap‑based distinct counting, dimension optimization techniques, and tight integration with HBase for storage and fast SQL querying.

Apache KylinBig DataCube
0 likes · 15 min read
Design Principles and Architecture of Apache Kylin for Sub‑Second OLAP Queries
ITPUB
ITPUB
Sep 27, 2019 · Artificial Intelligence

How Didi and Ant Financial Co‑Built SQLFlow to Bring AI to Data Analysts

The article describes how Didi's data science team partnered with Ant Financial to open‑source SQLFlow, a tool that translates SQL into Python for AI model training and inference, enabling analysts to use familiar SQL to run deep‑learning, XGBoost, and clustering models across diverse business scenarios.

AIMachine LearningSQL
0 likes · 9 min read
How Didi and Ant Financial Co‑Built SQLFlow to Bring AI to Data Analysts
Programmer DD
Programmer DD
Sep 27, 2019 · Databases

How to Use MySQL User Variables for Cumulative Daily User Counts

This article explains how to calculate cumulative daily user totals in MySQL using user-defined variables, demonstrates the necessary SQL queries, compares them with a Java‑style algorithm, and highlights important considerations such as variable initialization and practical pitfalls.

MySQLSQLcumulative sum
0 likes · 6 min read
How to Use MySQL User Variables for Cumulative Daily User Counts
ITPUB
ITPUB
Sep 19, 2019 · Databases

Why Hash Join Beats Nested Loop in MySQL 8.0 – Faster Queries & New EXPLAIN ANALYZE

MySQL 8.0 introduces Hash Join for dramatically faster large‑dataset queries, supports in‑memory and spill‑to‑disk processing, can replace Block Nested‑Loop joins, and adds EXPLAIN ANALYZE with detailed runtime statistics and tree‑style output, highlighting the platform’s rapid evolution.

Database PerformanceEXPLAIN ANALYZEHash Join
0 likes · 3 min read
Why Hash Join Beats Nested Loop in MySQL 8.0 – Faster Queries & New EXPLAIN ANALYZE
21CTO
21CTO
Sep 17, 2019 · Databases

Which Databases Dominated 2019? Rankings, Trends, and Management Insights

This article examines the most popular open‑source and commercial database systems in 2019, presents DB‑Engines rankings, explores single versus hybrid strategies, highlights popular SQL‑NoSQL combos, and identifies the most time‑consuming DBA tasks and key performance metrics.

DatabasesNoSQLRanking
0 likes · 7 min read
Which Databases Dominated 2019? Rankings, Trends, and Management Insights
FunTester
FunTester
Sep 12, 2019 · Backend Development

Scraping HTML Tables with Java Regex and Generating SQL Inserts

The article walks through a Java solution for extracting multilingual data from an HTML table using regular expressions, handling spacing and encoding issues, splitting fields, and constructing INSERT statements to populate a country_code database table.

JavaSQLWeb Scraping
0 likes · 6 min read
Scraping HTML Tables with Java Regex and Generating SQL Inserts
dbaplus Community
dbaplus Community
Sep 7, 2019 · Databases

How to Streamline DBA Code Reviews and Reclaim Your Weekends

A busy DBA can reduce weekend firefights by automating SQL code formatting, detecting injection risks, assessing performance impact, and fostering a collaborative review culture with developers through testing frameworks and knowledge‑sharing sessions.

Database AdministrationSQLTesting
0 likes · 7 min read
How to Streamline DBA Code Reviews and Reclaim Your Weekends
DataFunTalk
DataFunTalk
Sep 5, 2019 · Big Data

Apache Beam Architecture Principles and Practical Application

This article introduces Apache Beam as a unified programming model for batch and streaming data processing, explains its architecture, core components, advantages, extensibility, and demonstrates practical usage with KafkaIO, BeamSQL, and AIoT scenarios across multiple runners.

Apache BeamJavaKafka
0 likes · 16 min read
Apache Beam Architecture Principles and Practical Application
Architect's Tech Stack
Architect's Tech Stack
Sep 3, 2019 · Databases

Practical MySQL Slow Query Optimization: Case Studies and Techniques

This article presents a step‑by‑step analysis of several real‑world MySQL slow‑query problems, demonstrates how to reproduce the issues, examines execution plans, applies concrete optimizations such as removing function calls, adjusting date comparisons, adding bigint indexes, and explains the impact of different EXPLAIN types on performance.

EXPLAINMySQLSQL
0 likes · 12 min read
Practical MySQL Slow Query Optimization: Case Studies and Techniques
Efficient Ops
Efficient Ops
Sep 2, 2019 · Databases

Master MySQL Optimization: Strategies, Tools, and Best Practices

This comprehensive guide explains MySQL optimization philosophy, required participants, key dimensions, essential tools, step‑by‑step tuning procedures, hardware and system tuning, and detailed MySQL and InnoDB parameter settings to improve performance and reliability.

MySQLPerformance TuningSQL
0 likes · 18 min read
Master MySQL Optimization: Strategies, Tools, and Best Practices
Big Data Technology & Architecture
Big Data Technology & Architecture
Sep 2, 2019 · Databases

Apache Phoenix Tutorial: Quick Start, Data Types, DML, Indexes, Salted Tables, and Advanced Features

This comprehensive guide introduces Apache Phoenix as an HBase SQL layer, covering quick‑start steps, supported data types, DML syntax, salted tables to prevent hotspots, various secondary index types, bulk‑load methods, auto‑increment IDs, dynamic columns, pagination, query plan analysis, and data migration techniques.

Apache PhoenixData MigrationHBase
0 likes · 33 min read
Apache Phoenix Tutorial: Quick Start, Data Types, DML, Indexes, Salted Tables, and Advanced Features
dbaplus Community
dbaplus Community
Aug 29, 2019 · Databases

Inside PostgreSQL: How Queries Are Parsed, Optimized, and Executed

This article walks through PostgreSQL’s query processing pipeline—from parsing SQL into relational algebra, through semantic analysis, query rewriting, optimization techniques like sub‑query elimination and join ordering, to the executor’s sequential scan algorithm—illustrating each step with code snippets and diagrams.

Database OptimizerPostgreSQLQuery Processing
0 likes · 14 min read
Inside PostgreSQL: How Queries Are Parsed, Optimized, and Executed
Big Data Technology Architecture
Big Data Technology Architecture
Aug 29, 2019 · Databases

19 Common MySQL Optimization Techniques

This article presents nineteen practical MySQL optimization methods—including using EXPLAIN, limiting IN clause size, specifying columns in SELECT, proper use of LIMIT, avoiding costly ORDER BY RAND(), choosing between IN and EXISTS, leveraging full‑text indexes, and applying join and index best practices—to improve query performance and reduce resource consumption.

IndexesMySQLOptimization
0 likes · 11 min read
19 Common MySQL Optimization Techniques
Liangxu Linux
Liangxu Linux
Aug 27, 2019 · Databases

19 Essential MySQL Optimization Techniques Every Developer Should Know

This guide compiles nineteen practical MySQL optimization tips—from using EXPLAIN and avoiding costly IN clauses to leveraging full‑text indexes, proper pagination, and join strategies—providing concrete SQL examples and actionable advice to improve query performance and reduce resource consumption.

IndexingMySQLQuery Tuning
0 likes · 11 min read
19 Essential MySQL Optimization Techniques Every Developer Should Know
360 Tech Engineering
360 Tech Engineering
Aug 27, 2019 · Databases

Quicksql: A Unified Cross‑Data‑Source SQL Query Engine

Quicksql is an open‑source, cross‑data‑source SQL engine built on Apache Calcite that provides a unified, safe, and fast SQL interface, enabling users to query heterogeneous storage systems such as Hive, MySQL, Elasticsearch, and Druid through command‑line, API, or JDBC connections.

Apache CalciteData IntegrationSQL
0 likes · 6 min read
Quicksql: A Unified Cross‑Data‑Source SQL Query Engine
macrozheng
macrozheng
Aug 16, 2019 · Databases

Designing Home Page Recommendation Tables: SQL Schemas Explained

This article details the database table structures used for managing various homepage recommendation features—including brand, new product, popular product, subject, and advertisement tables—providing full MySQL DDL statements, field descriptions, and visual examples of both admin and mobile interfaces.

Backend DevelopmentDatabase DesignMySQL
0 likes · 6 min read
Designing Home Page Recommendation Tables: SQL Schemas Explained
Efficient Ops
Efficient Ops
Aug 15, 2019 · Fundamentals

Master SQL SELECT: 10 Steps to Understand Execution Order and Joins

This comprehensive guide explains how SQL's declarative nature, the mismatch between syntax and execution order, table references, various join types, derived tables, GROUP BY behavior, and key keywords like DISTINCT, UNION, ORDER BY, and OFFSET work together to help readers master SELECT statements.

Database FundamentalsJoinsQuery Execution
0 likes · 20 min read
Master SQL SELECT: 10 Steps to Understand Execution Order and Joins
DevOps Cloud Academy
DevOps Cloud Academy
Aug 13, 2019 · Databases

Step‑by‑Step Guide to Installing Oracle 12c Database on Linux

This article provides a comprehensive, ordered tutorial for preparing the environment, configuring the root and oracle users, adjusting kernel and system limits, and finally installing and initializing Oracle 12c on a Linux server using detailed command‑line instructions.

Database InstallationLinuxOracle
0 likes · 5 min read
Step‑by‑Step Guide to Installing Oracle 12c Database on Linux
Big Data Technology & Architecture
Big Data Technology & Architecture
Aug 12, 2019 · Big Data

Spark SQL Parameter Tuning and Performance Optimization (Spark 2.3.2)

This article explains how to troubleshoot and tune Spark SQL configuration parameters—covering exception‑related settings such as spark.sql.hive.convertMetastoreParquet, file‑ignore options, and partition verification, as well as performance‑focused tweaks like broadcast join thresholds, adaptive execution, and parquet schema merging—while providing a comprehensive parameter reference table.

Big DataHive MigrationSQL
0 likes · 23 min read
Spark SQL Parameter Tuning and Performance Optimization (Spark 2.3.2)
macrozheng
macrozheng
Aug 9, 2019 · Databases

Mastering Coupon System Design: Database Schemas and UI Integration

This article provides a comprehensive walkthrough of the coupon feature's database tables—including definitions for coupons, coupon history, product relations, and category relations—along with screenshots of both admin and mobile interfaces that illustrate how these tables are used in an e‑commerce system.

CouponSQLdatabase schema
0 likes · 6 min read
Mastering Coupon System Design: Database Schemas and UI Integration
Java Captain
Java Captain
Aug 7, 2019 · Databases

Practical Guide to Group, Join, and CASE WHEN Queries in SQL

This article provides a beginner‑friendly, step‑by‑step tutorial on common SQL operations—including GROUP BY aggregation, JOIN types, CASE WHEN expressions, and useful built‑in functions—illustrated with clear examples, typical pitfalls, and ready‑to‑use code snippets.

CASE WHENDatabase tutorialFunctions
0 likes · 10 min read
Practical Guide to Group, Join, and CASE WHEN Queries in SQL
21CTO
21CTO
Aug 6, 2019 · Databases

Why SQL Is Making a Comeback: From NoSQL’s Rise to the New Data Era

This article explores the resurgence of SQL, tracing its historical roots, the rise and limitations of NoSQL, and how modern cloud and NewSQL solutions are re‑establishing SQL as the universal interface for data storage, processing, and analysis.

Data EngineeringNewSQLNoSQL
0 likes · 14 min read
Why SQL Is Making a Comeback: From NoSQL’s Rise to the New Data Era
Programmer DD
Programmer DD
Aug 5, 2019 · Databases

Master MySQL Optimization: Practical Strategies to Boost Performance and Stability

This guide walks you through MySQL's query process, the philosophy and risks of optimization, the key participants, core dimensions such as hardware, system, schema and SQL, essential diagnostic tools, emergency and regular tuning steps, system‑level monitoring, kernel and user limits, as well as detailed MySQL and InnoDB configuration parameters for achieving high performance and reliability.

MySQLPerformance TuningSQL
0 likes · 15 min read
Master MySQL Optimization: Practical Strategies to Boost Performance and Stability
Aikesheng Open Source Community
Aikesheng Open Source Community
Jul 30, 2019 · Databases

Using MySQL 8.0 CLONE Plugin to Create Instance Replicas

This article explains how the MySQL 8.0 CLONE plugin simplifies creating reliable replica instances by installing the plugin, granting necessary privileges, executing the CLONE SQL statement, monitoring progress via performance_schema, and verifying successful completion of all clone stages.

InnoDBMySQLPerformance Schema
0 likes · 12 min read
Using MySQL 8.0 CLONE Plugin to Create Instance Replicas
ITPUB
ITPUB
Jul 25, 2019 · Databases

Master Oracle Database: Create, Backup, Restore, and Manage Tables & Data

This guide provides step‑by‑step Oracle commands for creating and dropping databases, performing full and selective backups, restoring data locally or remotely, managing tables—including creation, deletion, renaming, column alterations, primary keys, indexes, and views—as well as querying, inserting, updating, deleting, and copying data efficiently.

OracleSQLTable Operations
0 likes · 8 min read
Master Oracle Database: Create, Backup, Restore, and Manage Tables & Data
macrozheng
macrozheng
Jul 25, 2019 · Databases

Mastering Order Return Database Design: Schemas, Statuses, and UI Flow

This article provides a comprehensive walkthrough of the order return and return‑reason database tables, detailing each field, status codes, and the corresponding admin and mobile UI screens that illustrate how the return process works in an e‑commerce system.

SQLdatabase schemae-commerce
0 likes · 7 min read
Mastering Order Return Database Design: Schemas, Statuses, and UI Flow
macrozheng
macrozheng
Jul 18, 2019 · Databases

Unlocking Order Management: Complete Database Schema for E‑Commerce Orders

This article provides a detailed analysis of the order-related database tables—including orders, order items, operation history, and order settings—along with their fields, data types, and meanings, and showcases how these tables are presented in both admin and mobile interfaces of an e‑commerce system.

Backend DevelopmentDatabase DesignOrder Management
0 likes · 9 min read
Unlocking Order Management: Complete Database Schema for E‑Commerce Orders
macrozheng
macrozheng
Jul 16, 2019 · Backend Development

Unlocking E‑Commerce Product Management: Deep Dive into Database Schemas

This article walks through the core database tables that power product editing, SKU management, tiered pricing, full‑reduction discounts, member pricing, product reviews, verification records, and operation logs in an e‑commerce system, complete with SQL definitions and UI screenshots.

Backend DevelopmentDatabase DesignSQL
0 likes · 14 min read
Unlocking E‑Commerce Product Management: Deep Dive into Database Schemas
Aikesheng Open Source Community
Aikesheng Open Source Community
Jul 15, 2019 · Databases

Common Causes and Fixes for MySQL Error 1045 (Access Denied)

This article enumerates the typical reasons why MySQL returns error 1045 – such as connecting to the wrong host, using a non‑existent user, host‑based access restrictions, incorrect passwords, special characters in Bash, and missing SSL – and provides step‑by‑step commands to diagnose and resolve each issue.

Access deniedDatabase AuthenticationError 1045
0 likes · 9 min read
Common Causes and Fixes for MySQL Error 1045 (Access Denied)
Architecture Digest
Architecture Digest
Jul 15, 2019 · Databases

Oracle Database Troubleshooting: Common Scripts and Diagnostic Procedures

This article presents a practical guide for Oracle DBAs to quickly diagnose and resolve application‑related database issues by checking OS load, analyzing wait events, querying session and object details, capturing diagnostic dumps, and using scripted commands to kill sessions or restart the database.

DBAOraclePerformance
0 likes · 13 min read
Oracle Database Troubleshooting: Common Scripts and Diagnostic Procedures
Architecture Digest
Architecture Digest
Jul 11, 2019 · Databases

The Rise of Oracle and the Evolution of the Database Industry

This article chronicles the origins and growth of Oracle, the colorful personality of its founder Larry Ellison, the early development of relational databases, the fierce competition among IBM, Sybase, Borland and other vendors, and the later impact of open‑source and cloud‑computing trends on the database market.

Database historyLarry EllisonOracle
0 likes · 43 min read
The Rise of Oracle and the Evolution of the Database Industry
Qunar Tech Salon
Qunar Tech Salon
Jul 9, 2019 · Databases

SQL Fundamentals and Query Optimization Techniques for PostgreSQL

This article introduces SQL fundamentals, explains DDL/DML/DCL categories, and provides practical PostgreSQL query optimization techniques—including index selection, condition rewriting, sub‑query removal, expression and partial indexes, DDL decomposition, CTE usage, and key configuration parameters—to help developers and DBAs improve performance and maintainability.

Database PerformancePostgreSQLQuery Optimization
0 likes · 12 min read
SQL Fundamentals and Query Optimization Techniques for PostgreSQL
Aikesheng Open Source Community
Aikesheng Open Source Community
Jul 8, 2019 · Databases

Understanding and Resolving MySQL Table Fragmentation

This article explains MySQL table fragmentation, how to detect it with SHOW TABLE STATUS, the reasons such as frequent DELETE and UPDATE operations, demonstrates its effects, and presents cleanup methods like OPTIMIZE TABLE and engine conversion, showing significant space savings and query speed improvements.

MySQLOptimizationSQL
0 likes · 5 min read
Understanding and Resolving MySQL Table Fragmentation
JD Retail Technology
JD Retail Technology
Jul 3, 2019 · Databases

CB‑SQL: JD Retail’s Elastic Distributed Database Built on CockroachDB – Architecture and Implementation Details

The article introduces CB‑SQL, JD Retail’s next‑generation elastic database based on CockroachDB, and comprehensively explains its overview, layered architecture, storage replication, cluster management, MVCC, hybrid logical clocks, lock‑free distributed transactions, CDC changefeeds, and SQL interface support.

CDCCockroachDBMVCC
0 likes · 14 min read
CB‑SQL: JD Retail’s Elastic Distributed Database Built on CockroachDB – Architecture and Implementation Details
Programmer DD
Programmer DD
Jul 2, 2019 · Databases

Why MySQL LIMIT Slows Down on Large Offsets and How to Fix It

This article analyzes why MySQL LIMIT pagination becomes increasingly slow with larger offsets, presents six optimization techniques—including using primary keys, covering indexes, prepared statements, subqueries, and composite indexes—and provides experimental results that demonstrate dramatic performance improvements.

Index OptimizationMySQLPerformance
0 likes · 12 min read
Why MySQL LIMIT Slows Down on Large Offsets and How to Fix It
DataFunTalk
DataFunTalk
Jun 28, 2019 · Databases

Deep Dive into Phoenix Index Creation, Maintenance, and SQL Compilation

This article provides a detailed technical analysis of Phoenix's native index creation and maintenance mechanisms, the underlying source code for index building, the role of coprocessors, and the complete SQL compilation pipeline from parsing to execution, highlighting how hints and optimizers influence index usage.

CoprocessorHBasePhoenix
0 likes · 26 min read
Deep Dive into Phoenix Index Creation, Maintenance, and SQL Compilation
Programmer DD
Programmer DD
Jun 28, 2019 · Databases

19 Essential MySQL Optimization Techniques Every Developer Should Know

The article outlines 19 practical MySQL optimization methods—from using EXPLAIN and limiting IN clause size to proper pagination, index usage, and JOIN strategies—providing clear explanations and example SQL snippets to help developers improve query performance and reduce resource consumption.

MySQLPerformanceSQL
0 likes · 10 min read
19 Essential MySQL Optimization Techniques Every Developer Should Know
Python Crawling & Data Mining
Python Crawling & Data Mining
Jun 26, 2019 · Databases

Why Your MySQL Queries Run Slow and How to Fix Common Index Issues

This article explains why MySQL queries can become slow—covering occasional delays from dirty‑page flushing or lock contention and persistent slowness caused by missing, unused, or mis‑chosen indexes—while offering practical tips such as checking process lists, correcting index usage, and refreshing statistics.

MySQLPerformanceSQL
0 likes · 12 min read
Why Your MySQL Queries Run Slow and How to Fix Common Index Issues
Aikesheng Open Source Community
Aikesheng Open Source Community
Jun 24, 2019 · Databases

Using Window Functions in MySQL: From Session Variables and GROUP_CONCAT to Native ROW_NUMBER()

This article demonstrates how to achieve ranking and pagination in MySQL using pre‑8.0 techniques such as session variables and GROUP_CONCAT, then shows the simpler native window function syntax introduced in MySQL 8.0, with complete examples, sample data, and queries for finding low‑scoring students.

MySQLSQLWindow Functions
0 likes · 9 min read
Using Window Functions in MySQL: From Session Variables and GROUP_CONCAT to Native ROW_NUMBER()
Big Data Technology & Architecture
Big Data Technology & Architecture
Jun 20, 2019 · Big Data

Comprehensive Guide to Flink SQL: Background, New Features, Programming Model, Operators, Functions, and a Practical NBA Scoring Leader Example

This article provides an in‑depth overview of Flink SQL, covering its origins, the latest 1.7.0 and 1.8.0 enhancements, the underlying programming model, common operators and built‑in functions, and a complete end‑to‑end example that analyzes NBA scoring‑leader data using Flink SQL.

Apache FlinkBig DataData Engineering
0 likes · 27 min read
Comprehensive Guide to Flink SQL: Background, New Features, Programming Model, Operators, Functions, and a Practical NBA Scoring Leader Example
ITPUB
ITPUB
Jun 18, 2019 · Databases

Why MySQL LIMIT Pagination Slows Down and 6 Proven Optimization Techniques

This article examines why MySQL LIMIT pagination becomes slower as the offset grows, presents six practical methods—including direct LIMIT, primary‑key indexing, ordered index scans, prepared statements, sub‑queries, and joins—provides benchmark results on large tables, and distills actionable guidelines for designing covering and composite indexes to achieve fast, stable pagination.

Index OptimizationLIMITMySQL
0 likes · 12 min read
Why MySQL LIMIT Pagination Slows Down and 6 Proven Optimization Techniques
Big Data Technology & Architecture
Big Data Technology & Architecture
Jun 17, 2019 · Big Data

Understanding Spark SQL: Concepts, Queries, Data Sources, and Practical Examples

This article introduces Spark SQL fundamentals, including its architecture, DataFrame and Dataset abstractions, query methods, interoperability with RDD, user-defined functions, integration with Hive, data source handling, and provides step‑by‑step Scala code examples for loading data, performing aggregations, and solving common analytical tasks.

DataFramesHiveSQL
0 likes · 15 min read
Understanding Spark SQL: Concepts, Queries, Data Sources, and Practical Examples
Programmer DD
Programmer DD
Jun 6, 2019 · Databases

Why Your SQL Queries Are Slow: 15 Real‑World Causes & Fixes

This article examines a wide range of factors that can cause MySQL queries to run slowly—including network latency, OS and hardware bottlenecks, storage I/O scheduling, CPU power settings, RAID cache behavior, index design, implicit type conversion, execution plan errors, large data volumes, metadata locks, concurrent row updates, data skew, inefficient pagination, table schema choices, InnoDB dirty‑page flushing, and undo log retention—offering concrete examples and mitigation strategies for each scenario.

MySQLSQLSlow Query
0 likes · 19 min read
Why Your SQL Queries Are Slow: 15 Real‑World Causes & Fixes
dbaplus Community
dbaplus Community
Jun 5, 2019 · Databases

How to Scale SQL Databases for 20,000+ Concurrent Users: Single Instance, Sharding, and Read‑Write Separation

This article explains how to handle 20,000+ concurrent SQL requests by moving from a simple single‑instance setup to multi‑instance sharding and finally to read‑write separation, detailing the architectural decisions, routing algorithms, and practical limits for high‑traffic e‑commerce systems.

PerformanceSQLhigh concurrency
0 likes · 7 min read
How to Scale SQL Databases for 20,000+ Concurrent Users: Single Instance, Sharding, and Read‑Write Separation
dbaplus Community
dbaplus Community
Jun 5, 2019 · Databases

Boost Oracle Hierarchical Query Performance: Filtering, CBO, and Parallel Strategies

This article examines common performance pitfalls in Oracle hierarchical (CONNECT BY) queries, compares filtering after tree generation versus during traversal, explains why CBO estimates can be wildly inaccurate, and demonstrates how to rewrite queries with pipelined table functions and parallel hints for dramatic speed gains.

CBOHierarchical QueryOracle
0 likes · 9 min read
Boost Oracle Hierarchical Query Performance: Filtering, CBO, and Parallel Strategies
21CTO
21CTO
Jun 5, 2019 · Databases

12 Proven SQL Tricks to Supercharge Your Database Performance

This article presents twelve practical SQL optimization techniques—from using proper comparison operators and LIMIT clauses to indexing strategies and query consistency—to dramatically improve database query speed and overall application performance.

Performance TuningQuery PlanningSQL
0 likes · 5 min read
12 Proven SQL Tricks to Supercharge Your Database Performance
Tencent Database Technology
Tencent Database Technology
Jun 4, 2019 · Databases

From SEQUEL to JSON: Tracing the Evolution of SQL Standards

This article chronicles the origins, standardization process, historical milestones, learning resources, and conformance challenges of SQL standards, highlighting key ISO/IEC versions, the roles of major vendors, and the growing complexity of the language over more than three decades.

ANSIComplianceDatabase Standards
0 likes · 11 min read
From SEQUEL to JSON: Tracing the Evolution of SQL Standards
Java Captain
Java Captain
May 31, 2019 · Databases

Common MySQL Query Performance Issues and Optimization Techniques

This article examines frequent MySQL performance problems such as inefficient LIMIT pagination, implicit type conversion, sub‑query updates, mixed ordering, EXISTS usage, condition push‑down limits, early result set reduction, and intermediate result set optimization, providing rewritten SQL examples that dramatically improve execution speed.

IndexesMySQLPerformance Tuning
0 likes · 11 min read
Common MySQL Query Performance Issues and Optimization Techniques
Aikesheng Open Source Community
Aikesheng Open Source Community
May 30, 2019 · Databases

Oracle GoldenGate Migration Guide: Oracle to MySQL Data Replication

This article provides a comprehensive step‑by‑step guide for migrating data from Oracle to MySQL using Oracle GoldenGate, covering architecture overview, environment setup, table and data migration, configuration of source and target processes, handling of common issues, data validation, and reference resources.

Data MigrationOGGOracle GoldenGate
0 likes · 22 min read
Oracle GoldenGate Migration Guide: Oracle to MySQL Data Replication
Programmer DD
Programmer DD
May 29, 2019 · Backend Development

MyBatis Pitfalls and Best Practices: A Guide for Java Developers

Discover the most common MyBatis pitfalls—from # vs $ usage, handling nulls, resultMap quirks, and dynamic SQL issues—to master safe query practices, optimize performance, and avoid runtime errors, while comparing its strengths and weaknesses against Hibernate for effective Java backend development.

Backend DevelopmentJavaMyBatis
0 likes · 23 min read
MyBatis Pitfalls and Best Practices: A Guide for Java Developers
dbaplus Community
dbaplus Community
May 26, 2019 · Databases

Why Is MySQL Query Slow? Common Causes and How to Diagnose Them

This article explains why a MySQL statement may run slowly—whether only occasionally or every time—by examining redo‑log flushing, lock contention, missing or misused indexes, optimizer mis‑estimates, and provides practical commands to identify and resolve each issue.

IndexesMySQLQuery Optimization
0 likes · 12 min read
Why Is MySQL Query Slow? Common Causes and How to Diagnose Them
Programmer DD
Programmer DD
May 15, 2019 · Backend Development

Why MyBatis Runs Extra SQLs and How to Tune Its Cache

This article explains why MyBatis may execute unexpected additional SQL statements, reveals the default caching behavior, shows the required XML configuration and Serializable implementation, and offers practical steps to prevent cache clearing on inserts for more efficient backend data access.

CacheJavaMyBatis
0 likes · 3 min read
Why MyBatis Runs Extra SQLs and How to Tune Its Cache
Alibaba Cloud Developer
Alibaba Cloud Developer
May 8, 2019 · Artificial Intelligence

How SQLFlow Lets You Build AI Models with Just a Few SQL Commands

SQLFlow, an open‑source project from Ant Financial, bridges SQL engines and AI frameworks so that users can train and predict machine‑learning models with simple SQL statements, dramatically lowering the technical barrier for analysts and engineers across diverse data platforms.

Artificial IntelligenceSQLSQLFlow
0 likes · 14 min read
How SQLFlow Lets You Build AI Models with Just a Few SQL Commands
AntTech
AntTech
May 7, 2019 · Artificial Intelligence

SQLFlow: Bridging SQL Engines and AI Platforms for End‑to‑End Machine Learning

SQLFlow is an open‑source project that connects diverse SQL engines (MySQL, Hive, SparkSQL, etc.) with AI frameworks (TensorFlow, PyTorch, XGBoost, etc.) through extended SQL syntax, enabling analysts to train and predict models using only a few SQL statements while aiming for high scalability and performance.

AI integrationMachine LearningSQL
0 likes · 13 min read
SQLFlow: Bridging SQL Engines and AI Platforms for End‑to‑End Machine Learning
Aikesheng Open Source Community
Aikesheng Open Source Community
May 7, 2019 · Databases

Understanding MySQL 8.0 Index Skip Scan (ISS)

MySQL 8.0 introduces Index Skip Scan (ISS), allowing queries that filter on non‑leftmost columns of a composite index to use the index without creating additional indexes, improving performance especially when the leftmost column has few distinct values, as demonstrated with example tables and execution plans.

ISSIndex Skip ScanMySQL
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Understanding MySQL 8.0 Index Skip Scan (ISS)
Aikesheng Open Source Community
Aikesheng Open Source Community
May 6, 2019 · Databases

How MySQL Finally Supports CHECK Constraints and Why It Matters for Data Integrity

This article explains why MySQL lacked CHECK constraints for years, demonstrates the data quality issues caused by missing checks, shows how to work around them with unsigned types, and provides step‑by‑step examples of using the new CHECK constraint in MySQL 8.0.16+ while highlighting its absence in earlier versions.

CHECK constraintDomain integrityMySQL
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How MySQL Finally Supports CHECK Constraints and Why It Matters for Data Integrity
Big Data Technology & Architecture
Big Data Technology & Architecture
Apr 24, 2019 · Big Data

Hive SQL Optimization Techniques and Best Practices

This article provides a comprehensive guide to Hive SQL performance tuning, covering optimization goals, common pitfalls, execution flow, table and job settings, map, shuffle, reduce, and query-level improvements such as join, bucket join, group‑by, and count‑distinct optimizations.

Big DataHadoopHive
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Hive SQL Optimization Techniques and Best Practices
DataFunTalk
DataFunTalk
Apr 24, 2019 · Big Data

Practical Experience with Druid SQL and Security at Meituan: Challenges, Improvements, and Best Practices

This article presents Meituan's real‑world experience with Apache Druid, detailing the platform’s current usage, the usability, security and stability challenges faced, the principles and architecture of Druid SQL, the enhancements made to schema inference, logging, query safety, and the custom security extensions implemented to achieve fine‑grained access control and SSO integration.

DruidOLAPPlatform
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Practical Experience with Druid SQL and Security at Meituan: Challenges, Improvements, and Best Practices