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TDSQL-C for MySQL

DocumentationTDSQL-C for MySQLKernel FeaturesInspection and Repair of Kernel IssuesInstant add column Causes rollback Failure After Upgrading to a Later Version When Page Data Occupancy Exceeds 50%

Instant add column Causes rollback Failure After Upgrading to a Later Version When Page Data Occupancy Exceeds 50%

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Last updated: 2025-12-08 15:56:17

Problem

The Instant add column operation causes page data occupancy to exceed 50%, resulting in rollback failure when an upgrade to a higher version is performed.

Issue Triggering Scenario

In versions of TXSQL 8.0 prior to 3.1.15.002, Instant add column operations were permitted even when row sizes exceeded half the page size. After the kernel version is upgraded, rollback operations may fail due to row size exceeding limitations during rollback events.

Kernel Version Related to the Issue

TXSQL 8.0 versions prior to 3.1.15.002.

Fixed Kernel Version

TXSQL 8.0 3.1.16.003.

Check Method

You can refer to the following command to scan for tables with potential risks.
select replace(name, '/', '.') as 'table_schema.table_name' from information_schema.innodb_tables where TOTAL_ROW_VERSIONS!=0 or INSTANT_COLS!=0;

Fixing Method

1. Upgrade the kernel version to TXSQL 8.0 3.1.16.003. For the procedure, see Upgrading the minor version of the kernel.
2. After the kernel version is upgraded, rebuild and repair corrupted tables using alter table xx engine = innodb;. To avoid business impact caused by table locking, it is recommended to perform repairs during off-peak hours using tools such as pt-osc.

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