The article explains the three primary MySQL data removal commands—DELETE, TRUNCATE, and DROP—detailing their execution speed, underlying mechanisms, impact on disk space for InnoDB and MyISAM engines, and best‑practice usage such as running OPTIMIZE TABLE after DELETE.
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.
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.
The article explains how JD’s Activity Cockpit tackles mega‑sale challenges by monitoring the consumer golden‑link, applying Optimize Table, BitMap, and materialized view techniques to reduce data volume, accelerate queries, and enable precise real‑time marketing for brands.
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.
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.
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.
This article explains why deleting rows in MySQL does not decrease the physical table file size, describes the underlying InnoDB storage mechanisms, and shows how to reclaim space using OPTIMIZE TABLE, ALTER TABLE, and Online DDL options.
The article explains how CDB introduced an InnoDB index physical space usage statistic to help users decide when to run OPTIMIZE TABLE, describes the background of page fragmentation, compares incremental and full‑scan methods, and details a sequential I/O optimization that dramatically reduces measurement time.
This article explains how to identify table and index fragmentation in MySQL using the Data_free column, and provides two effective repair methods—altering the table engine and running OPTIMIZE TABLE—while warning about resource consumption and recommending a monthly maintenance schedule.
