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Su San Talks Tech
Su San Talks Tech
May 5, 2026 · Databases

Alibaba Interview: Key Considerations for Indexing Tens‑Millions‑Row Tables

The article explains how to safely add indexes to a tens‑of‑millions‑row MySQL table, covering lock duration, disk‑space impact, write‑performance degradation, and six practical principles—selective columns, proper order, covering indexes, avoiding redundancy, short‑lock tools, and ongoing monitoring—plus pros, cons, and suitable use cases.

Large TablesOnline DDLPerformance Monitoring
0 likes · 10 min read
Alibaba Interview: Key Considerations for Indexing Tens‑Millions‑Row Tables
Spring Full-Stack Practical Cases
Spring Full-Stack Practical Cases
Apr 3, 2026 · Databases

10 Must‑Know MySQL Advanced Techniques to Supercharge Performance

This article presents ten practical MySQL advanced techniques—including EXPLAIN analysis, composite and covering indexes, index condition push‑down, prefix indexes, window functions, CTEs, JSON handling, partition tables, join optimizations, variables, online DDL, and generated columns—each illustrated with real‑world SQL examples and execution‑plan screenshots to boost efficiency in high‑volume, high‑concurrency environments.

Advanced SQLCTEIndex Optimization
0 likes · 16 min read
10 Must‑Know MySQL Advanced Techniques to Supercharge Performance
Ray's Galactic Tech
Ray's Galactic Tech
Jan 12, 2026 · Databases

How to Safely Add Columns to Billion‑Row MySQL Tables Without Downtime

This guide explains why using a plain ALTER TABLE on massive MySQL tables can lock the table and halt services, and presents tool‑based online DDL, native INPLACE options, phased migration strategies, cloud‑DB features, best‑practice checks, monitoring, and rollback techniques to add new columns safely.

Online DDLSchema Changedatabase migration
0 likes · 8 min read
How to Safely Add Columns to Billion‑Row MySQL Tables Without Downtime
ITPUB
ITPUB
Jan 11, 2026 · Databases

6 Proven Strategies to Add Columns to Billion‑Row MySQL Tables Without Downtime

This article examines why adding a column to a MySQL table with tens of millions of rows can lock the table, then presents six practical solutions—including native online DDL, PT‑OSC, gh‑ost, dual‑write migration, maintenance downtime, and partition sliding‑window—detailing their procedures, trade‑offs, and suitable scenarios.

Database operationsLarge TablesOnline DDL
0 likes · 12 min read
6 Proven Strategies to Add Columns to Billion‑Row MySQL Tables Without Downtime
Top Architect
Top Architect
Dec 15, 2025 · Databases

How to Add a Column to a Billion‑Row Order Table Without Downtime

When a core order table with tens of millions of rows needs a new column, naïve ALTER TABLE can lock the table and disrupt services, so this article explores safe alternatives such as master‑slave switching, online DDL tools, extension tables, JSON‑based schema‑less designs, and clever reuse of existing redundant fields, complete with practical code snippets and lessons learned.

DDLJSONOnline DDL
0 likes · 9 min read
How to Add a Column to a Billion‑Row Order Table Without Downtime
Aikesheng Open Source Community
Aikesheng Open Source Community
Dec 10, 2025 · Databases

Why OceanBase DDL Expansion Can Crash Your Service and How to Fix It

A production migration from Oracle to OceanBase caused a column‑length change to trigger offline DDL, leading to connection errors, INSERT latency spikes, and complete table blockage; the article reproduces the fault, analyzes the OMS conversion and OceanBase DDL rules, and provides a two‑step remediation and a method to verify online DDL execution.

DDLOceanBaseOffline DDL
0 likes · 11 min read
Why OceanBase DDL Expansion Can Crash Your Service and How to Fix It
Top Architect
Top Architect
Dec 3, 2025 · Backend Development

How to Add a Column to a Billion‑Row Order Table Without Breaking Production

When a new business field is required on a core order table with tens of millions of rows, the article walks through the risks of direct ALTER TABLE, evaluates master‑slave switching, online DDL tools, extension tables, JSON‑based schema‑less designs, and a clever reuse of an existing redundant column, providing practical steps and performance insights.

ALTER TABLEJSON columnOnline DDL
0 likes · 9 min read
How to Add a Column to a Billion‑Row Order Table Without Breaking Production
dbaplus Community
dbaplus Community
Nov 17, 2025 · Databases

6 Proven Strategies to Safely Add Columns to Massive MySQL Tables

When adding a column to a MySQL table with tens of millions of rows, lock contention can cripple services, so this guide compares six practical solutions—including native online DDL, PT‑OSC, gh‑ost, partition sliding windows, downtime maintenance, and dual‑write migration—detailing their mechanisms, trade‑offs, use‑cases, and step‑by‑step commands to ensure minimal disruption.

Database operationsLarge TablesOnline DDL
0 likes · 12 min read
6 Proven Strategies to Safely Add Columns to Massive MySQL Tables
Architect
Architect
Oct 12, 2025 · Databases

How to Safely Add a Column to a Billion‑Row Order Table Without Downtime

Adding a new field to a core order table with tens of millions of rows can lock the table and disrupt services, so this article explores various strategies—including master‑slave switching, online DDL tools, extension tables, JSON fields, and repurposing redundant columns—to achieve schema changes safely and efficiently.

JSON fieldOnline DDLSchema Change
0 likes · 8 min read
How to Safely Add a Column to a Billion‑Row Order Table Without Downtime
Architect's Tech Stack
Architect's Tech Stack
Sep 22, 2025 · Databases

How to Safely Add a Column to a Billion-Row Order Table Without Downtime

When a core order table with tens of millions of rows needs a new business field, directly running ALTER TABLE can lock the table and disrupt services, so this article explores master‑slave switching, online DDL tools, extension tables, JSON fields, and clever reuse of existing redundant columns to achieve the change safely and efficiently.

JSON fieldLarge TablesOnline DDL
0 likes · 9 min read
How to Safely Add a Column to a Billion-Row Order Table Without Downtime
Java Tech Enthusiast
Java Tech Enthusiast
Aug 26, 2025 · Databases

6 Proven Strategies to Safely Add Columns to Billion‑Row MySQL Tables

This article explores why adding columns to massive MySQL tables can lock the database, explains the risks, and presents six practical solutions—including native online DDL, downtime maintenance, PT‑OSC, logical migration with dual writes, gh‑ost, and partition sliding windows—along with best‑practice tips for monitoring, backup, and performance.

Large TablesOnline DDLSchema Migration
0 likes · 11 min read
6 Proven Strategies to Safely Add Columns to Billion‑Row MySQL Tables
Xiaolei Talks DB
Xiaolei Talks DB
May 16, 2025 · Databases

How Online DDL Impacts TPS/QPS in OceanBase: A Comprehensive Test

This article details a systematic performance test of OceanBase's online DDL capabilities, measuring TPS and QPS impacts across various DDL operations, describing the test environment, scripts, results, and conclusions for reliable database schema changes.

OceanBaseOnline DDLQPS
0 likes · 17 min read
How Online DDL Impacts TPS/QPS in OceanBase: A Comprehensive Test
Java Tech Enthusiast
Java Tech Enthusiast
Apr 4, 2025 · Databases

MySQL Large Table Index Optimization and Batch Deletion Strategies

By dropping a low‑selectivity composite index, adding targeted indexes on product_id‑sequence‑station_no and receive_time, and using online DDL with pt‑osc, the team reduced row scans and replication lag, then implemented batch deletions by primary‑key ranges, cutting delete time from minutes to seconds on a 100‑million‑row table.

Batch DeletionIndex OptimizationLarge Tables
0 likes · 14 min read
MySQL Large Table Index Optimization and Batch Deletion Strategies
dbaplus Community
dbaplus Community
Feb 6, 2025 · Databases

How a MySQL Online Schema Change Platform Evolved from a Single‑Lane Bridge to a Robust 2.0 System

This article recounts the development of ZzoOnlineDDL, a MySQL schema‑change platform, detailing its 1.0 limitations, the 2.0 architectural upgrades, feature set—including intelligent tool selection, timed execution, sharding support, monitoring, and retry mechanisms—and lessons learned from real‑world incidents such as MDL locks, disk pressure, and unique‑index pitfalls.

Online DDLSchema Changegh-ost
0 likes · 34 min read
How a MySQL Online Schema Change Platform Evolved from a Single‑Lane Bridge to a Robust 2.0 System
vivo Internet Technology
vivo Internet Technology
Aug 7, 2024 · Databases

MySQL 5.7 DDL vs GH-OST: A Comprehensive Comparison of Online Schema Change Tools

While MySQL 5.7 native DDL methods (copy, inplace rebuild, index build, metadata‑only) vary in speed, space use, lock impact, and binlog output, GH‑OST consistently offers the fastest execution, lowest lock blocking, real‑time replication, albeit at roughly double storage cost, making it ideal for risk‑averse online schema changes.

DDLInnoDBOnline DDL
0 likes · 11 min read
MySQL 5.7 DDL vs GH-OST: A Comprehensive Comparison of Online Schema Change Tools
Aikesheng Open Source Community
Aikesheng Open Source Community
May 7, 2024 · Databases

Why Expanding a MySQL VARCHAR Column from 63 to 64 Characters Takes Much Longer

The article investigates why altering a MySQL VARCHAR column from a length that fits within 255 bytes to one that exceeds this limit (e.g., VARCHAR(63) to VARCHAR(64) in utf8mb4) triggers a costly copy operation, analyzes the storage mechanics, reproduces the issue, and provides practical recommendations to avoid performance penalties.

Character SetDatabase AdministrationOnline DDL
0 likes · 13 min read
Why Expanding a MySQL VARCHAR Column from 63 to 64 Characters Takes Much Longer
Architect
Architect
Apr 29, 2024 · Databases

How to Slash MySQL Slow Queries on a 100M‑Row Table: Index Tuning and Batch Deletion

The article walks through a real‑world MySQL performance case where a 100‑million‑row table caused SLA alerts, analyzes slow‑query logs, demonstrates index redesign, compares online DDL with pt‑osc, and shows how batch deletions by primary key dramatically reduce delete time and replication lag.

Batch DeleteIndex OptimizationLarge Table
0 likes · 15 min read
How to Slash MySQL Slow Queries on a 100M‑Row Table: Index Tuning and Batch Deletion
Aikesheng Open Source Community
Aikesheng Open Source Community
Jan 30, 2024 · Databases

Troubleshooting VARCHAR Column Expansion Issues with MySQL Online DDL

This article analyzes why ALTER TABLE operations that extend VARCHAR columns sometimes fail in MySQL, explains the underlying Online DDL constraints, presents several real‑world problems such as default‑value handling, indexed columns, and hidden table‑rebuild quirks, and offers practical solutions for each case.

ALTER TABLEDatabase AdministrationOnline DDL
0 likes · 17 min read
Troubleshooting VARCHAR Column Expansion Issues with MySQL Online DDL
Code Ape Tech Column
Code Ape Tech Column
Jun 12, 2023 · Databases

Understanding MySQL DDL Execution and Online DDL Mechanisms

This article explains the differences between MySQL DDL and DML, describes how online DDL works—including copy and inplace algorithms, execution phases, common pitfalls, limitations, and recent MySQL 8.0 enhancements—providing practical guidance for safely altering large tables.

DDLInnoDBOnline DDL
0 likes · 16 min read
Understanding MySQL DDL Execution and Online DDL Mechanisms
Java High-Performance Architecture
Java High-Performance Architecture
Oct 5, 2022 · Databases

How to Optimize Massive MySQL Tables: Index Tuning, Online DDL, and Batch Deletion Strategies

This article analyzes a large MySQL table with frequent SLA alerts, demonstrates how to identify slow queries using pt‑query‑digest, proposes index redesign and online DDL versus pt‑osc methods, and shows testing, implementation, and batch‑delete techniques to dramatically reduce query time and maintenance overhead.

Batch DeletionDatabase MaintenanceIndex Optimization
0 likes · 17 min read
How to Optimize Massive MySQL Tables: Index Tuning, Online DDL, and Batch Deletion Strategies
21CTO
21CTO
Sep 28, 2022 · Databases

How to Optimize Large MySQL Tables: Index Tuning, Online DDL, and Batch Deletion

This article walks through diagnosing slow‑query problems on a massive MySQL table, reveals index misuse, proposes dropping the old composite index, adding targeted indexes, using online DDL or pt‑osc for schema changes, and applying batch‑delete techniques to reduce latency and storage fragmentation.

Batch DeletionIndex OptimizationLarge Tables
0 likes · 14 min read
How to Optimize Large MySQL Tables: Index Tuning, Online DDL, and Batch Deletion
Java Backend Technology
Java Backend Technology
Sep 27, 2022 · Databases

Optimizing Massive MySQL Tables: Index Tuning, Online DDL & Batch Deletion

Facing SLA alerts due to slow queries on a billion‑row MySQL table, the article analyzes slow‑query logs, reveals index misuse, and demonstrates how removing a poor composite index, adding targeted indexes, employing online DDL or pt‑osc, and using batch deletions dramatically reduce query times and maintenance overhead.

Batch DeletionLarge TablesOnline DDL
0 likes · 16 min read
Optimizing Massive MySQL Tables: Index Tuning, Online DDL & Batch Deletion
Aikesheng Open Source Community
Aikesheng Open Source Community
May 26, 2022 · Databases

Resolving Xtrabackup Backup Failures Caused by Non‑Redo Logging DDL Operations in MySQL 5.7

This article analyses why physical backups using Xtrabackup fail when MySQL 5.7 performs online DDL operations that skip redo logging, demonstrates the issue with real‑world logs, and presents four practical solutions—including lock‑DDL parameters, per‑table MDL locks, and disabling online DDL—to ensure consistent backups.

DDLOnline DDLSorted Index Build
0 likes · 23 min read
Resolving Xtrabackup Backup Failures Caused by Non‑Redo Logging DDL Operations in MySQL 5.7
dbaplus Community
dbaplus Community
Feb 10, 2022 · Databases

Why MySQL Delete Doesn’t Free Space and How InnoDB Reclaims It

This article explains why MySQL’s DELETE only sets a delete‑mark, how InnoDB’s MVCC and purge thread reuse freed pages, the impact of B+‑tree storage on I/O, page merge and split mechanisms, and the proper way to rebuild tables to recover space.

B+TreeDatabase StorageDelete Mark
0 likes · 14 min read
Why MySQL Delete Doesn’t Free Space and How InnoDB Reclaims It
Top Architect
Top Architect
Dec 5, 2021 · Databases

Why MySQL Table Size Does Not Decrease After DELETE and How to Reduce It

This article explains why deleting rows in MySQL does not shrink the underlying table file, describes the InnoDB storage mechanics that cause this behavior, and provides practical solutions such as OPTIMIZE TABLE, ALTER TABLE, and Online DDL to reclaim space and avoid table‑locking issues.

ALTER TABLEDELETEInnoDB
0 likes · 8 min read
Why MySQL Table Size Does Not Decrease After DELETE and How to Reduce It
Programmer DD
Programmer DD
Aug 29, 2021 · Databases

Why MySQL DELETE Doesn’t Shrink Table Size and How to Fix It

This article explains why MySQL's DELETE command only marks rows as reusable without shrinking the .ibd file, describes the underlying B+‑tree storage mechanism, and provides practical solutions such as OPTIMIZE TABLE, ALTER TABLE, and online DDL options to reclaim space and avoid table‑level locks.

DELETEInnoDBOnline DDL
0 likes · 7 min read
Why MySQL DELETE Doesn’t Shrink Table Size and How to Fix It
Top Architect
Top Architect
Jul 19, 2021 · Databases

Why MySQL DELETE Does Not Reduce Table File Size and How to Shrink It

The article explains why deleting rows in MySQL does not shrink the physical table file, describes the underlying InnoDB storage mechanisms, and provides practical methods such as OPTIMIZE TABLE, ALTER TABLE, and Online DDL to reclaim space and reorganize the table.

ALTER TABLEDELETEDatabase Maintenance
0 likes · 7 min read
Why MySQL DELETE Does Not Reduce Table File Size and How to Shrink It
360 Smart Cloud
360 Smart Cloud
Apr 1, 2021 · Databases

Using TiDB Data Migration (DM) for MySQL‑to‑TiDB Sync: Architecture, Features, Tuning and Troubleshooting

This article shares practical experience with TiDB Data Migration (DM), covering its background, architecture, key features, online DDL support, common error handling such as duplicate‑key issues, large‑scale import tuning, configuration limits, and cleanup recommendations for reliable MySQL‑to‑TiDB synchronization.

DMData MigrationDatabase Synchronization
0 likes · 16 min read
Using TiDB Data Migration (DM) for MySQL‑to‑TiDB Sync: Architecture, Features, Tuning and Troubleshooting
Aikesheng Open Source Community
Aikesheng Open Source Community
Dec 8, 2020 · Databases

Understanding MySQL Online DDL for VARCHAR Column Size Changes and In‑Place vs Copy Operations

The article explains how MySQL's Online DDL handles VARCHAR column expansions, demonstrates performance differences across character sets using sysbench, and clarifies why certain size changes trigger in‑place alterations while others require full table copies, providing practical guidance for DBAs.

Character SetInnoDBOnline DDL
0 likes · 9 min read
Understanding MySQL Online DDL for VARCHAR Column Size Changes and In‑Place vs Copy Operations
360 Tech Engineering
360 Tech Engineering
Dec 4, 2020 · Databases

Practical Experience and Tips with TiDB Data Migration (DM) Tool

This article shares a comprehensive overview of TiDB Data Migration (DM), covering its architecture, configuration, online DDL support, common pitfalls such as duplicate‑key errors, large‑scale import tuning, version limits, and cleanup recommendations to help DBAs efficiently migrate MySQL/MariaDB workloads to TiDB.

DMData MigrationOnline DDL
0 likes · 16 min read
Practical Experience and Tips with TiDB Data Migration (DM) Tool
Aikesheng Open Source Community
Aikesheng Open Source Community
Sep 16, 2020 · Databases

Online DDL Tool pt-osc: Principles, Usage, and Comparison

This article provides a comprehensive guide to the pt-online-schema-change (pt-osc) tool for MySQL online DDL, covering its underlying mechanism, limitations, installation steps, command‑line syntax, practical examples, and a comparative analysis with native Online DDL and gh‑ost to help users choose the appropriate solution.

Online DDLdatabase migrationmysql
0 likes · 32 min read
Online DDL Tool pt-osc: Principles, Usage, and Comparison
21CTO
21CTO
Jul 9, 2020 · Databases

How to Optimize Large MySQL Tables: Index Tuning, Online DDL, and Efficient Deletion

This article walks through diagnosing severe SLA alerts caused by slow queries on a massive MySQL table, analyzes query patterns with pt‑query‑digest, redesigns indexes, applies online DDL and pt‑osc for index changes, and demonstrates batch‑delete techniques that dramatically reduce execution time and replication lag.

Batch DeleteIndex OptimizationLarge Tables
0 likes · 15 min read
How to Optimize Large MySQL Tables: Index Tuning, Online DDL, and Efficient Deletion
Laravel Tech Community
Laravel Tech Community
May 18, 2020 · Databases

MySQL Large‑Table Index Optimization and Delete Performance Improvement

This article analyzes a MySQL master‑slave instance with a massive arrival_record table, identifies slow‑query causes using pt‑query‑digest and tcpdump, proposes index redesign, demonstrates backup/restore with mydumper, compares online DDL and pt‑osc, and presents batch‑delete strategies that dramatically reduce SLA‑triggering latency.

BackupBatch DeleteIndex Optimization
0 likes · 14 min read
MySQL Large‑Table Index Optimization and Delete Performance Improvement
Java Backend Technology
Java Backend Technology
Apr 5, 2020 · Databases

How to Optimize Massive MySQL Tables: Index Tuning, Online DDL, and Batch Deletion

This article walks through diagnosing severe SLA alerts caused by slow queries on a huge MySQL table, using pt‑query‑digest and tcpdump to uncover index misuse, then proposes new composite and single‑column indexes, demonstrates online DDL versus pt‑osc, and shows how batch deletions and efficient backup/restore dramatically reduce execution time and replication lag.

Batch DeleteOnline DDLSlow query analysis
0 likes · 16 min read
How to Optimize Massive MySQL Tables: Index Tuning, Online DDL, and Batch Deletion
Qunar Tech Salon
Qunar Tech Salon
Aug 21, 2015 · Databases

Comprehensive Guide to MySQL: History, Advantages, Issues, Development Standards, Operations, and Performance Optimization

This article provides an extensive overview of MySQL, covering its history, strengths and limitations, recommended development and operational standards, replication and high‑availability strategies, backup and recovery methods, as well as detailed performance‑tuning techniques for InnoDB and alternative storage engines.

Database designInnoDBOnline DDL
0 likes · 28 min read
Comprehensive Guide to MySQL: History, Advantages, Issues, Development Standards, Operations, and Performance Optimization