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Database Maintenance

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Aikesheng Open Source Community
Aikesheng Open Source Community
Oct 9, 2023 · Databases

Using MySQL Offline Mode to Disconnect Client Connections

This article explains how MySQL's offline_mode variable and the pt‑kill tool can be used by DBAs to place a server in maintenance mode, instantly dropping non‑privileged client connections, preventing new ones, and providing a safe way to perform maintenance or backups.

Database MaintenanceMySQLOFFLINE_MODE
0 likes · 8 min read
Using MySQL Offline Mode to Disconnect Client Connections
Top Architect
Top Architect
Sep 17, 2022 · Databases

Optimizing Large MySQL Tables: Index Tuning, Slow Query Analysis, and Efficient Deletion Strategies

This article details a comprehensive analysis of a large MySQL table's performance issues, including slow query diagnostics with pt‑query‑digest, index evaluation, backup and restore procedures, online DDL versus pt‑osc, and practical strategies for index redesign and batch deletions to reduce latency and maintenance overhead.

DDLDatabase MaintenanceIndex Optimization
0 likes · 14 min read
Optimizing Large MySQL Tables: Index Tuning, Slow Query Analysis, and Efficient Deletion Strategies
Top Architect
Top Architect
Nov 17, 2021 · Databases

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

The article explains why MySQL’s DELETE command does not shrink the physical table file, describes InnoDB’s storage mechanics, and shows how to reclaim space using OPTIMIZE TABLE, ALTER TABLE, and Online DDL options.

ALTER TABLEDELETEDatabase Maintenance
0 likes · 7 min read
Why MySQL Table Size Does Not Decrease After DELETE and How to Reduce 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
Aikesheng Open Source Community
Aikesheng Open Source Community
Jun 28, 2021 · Databases

How to Check and Optimize MySQL Table Space Fragmentation

This article explains how to detect table‑space fragmentation in MySQL, demonstrates the performance impact of deleted rows, and provides step‑by‑step commands—including ALTER TABLE FORCE, OPTIMIZE TABLE, and mysqlcheck—to reclaim space and improve query speed.

Database MaintenanceMySQLOptimization
0 likes · 8 min read
How to Check and Optimize MySQL Table Space Fragmentation
Full-Stack Internet Architecture
Full-Stack Internet Architecture
Jun 10, 2021 · Databases

MySQL Optimization: SQL Tuning Steps, Index Usage, and Table Maintenance

This article, the fourth in a MySQL fundamentals series, explains how to diagnose and optimize slow SQL statements using SHOW STATUS, the slow‑query log, SHOW PROCESSLIST, and EXPLAIN, then details index types, creation, usage rules, and how to analyze, check, and optimize tables with MySQL commands.

Database MaintenanceEXPLAINIndexes
0 likes · 22 min read
MySQL Optimization: SQL Tuning Steps, Index Usage, and Table Maintenance
Top Architect
Top Architect
Jun 9, 2021 · Databases

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

The article explains why deleting rows in MySQL does not shrink the .ibd file because InnoDB only marks pages as reusable, and shows how to reclaim space using OPTIMIZE TABLE, ALTER TABLE, and Online DDL options.

ALTER TABLEDELETEDatabase Maintenance
0 likes · 7 min read
Why MySQL DELETE Does Not Reduce Table Size and How to Shrink It
360 Tech Engineering
360 Tech Engineering
May 31, 2021 · Databases

Understanding MongoDB TTL Indexes: Concepts, Operation, Creation Methods, Limitations, and Best Practices

This article explains MongoDB TTL indexes, covering their basic concept as single‑field auto‑deletion indexes, how the background process works, alternative creation methods using an expireAt field, practical limitations, and recommendations for designing efficient data expiration strategies.

Data ExpirationDatabase MaintenanceMongoDB
0 likes · 7 min read
Understanding MongoDB TTL Indexes: Concepts, Operation, Creation Methods, Limitations, and Best Practices
Aikesheng Open Source Community
Aikesheng Open Source Community
Apr 28, 2021 · Databases

Using pt-archiver for Batch Deletion of Large MySQL Tables

The article explains why massive MySQL tables need periodic cleanup, compares risky drop/truncate approaches, and provides a step‑by‑step guide to safely delete historical data in batches using pt‑archiver with proper parameters, session handling, and post‑deletion maintenance.

Data CleanupDatabase MaintenanceMySQL
0 likes · 7 min read
Using pt-archiver for Batch Deletion of Large MySQL Tables