MySQL Bugs: #94330: Test for possible compressed failures before upgrade?

Bug #94330	Test for possible compressed failures before upgrade?
Submitted:	14 Feb 2019 20:19	Modified:	17 Oct 2019 14:58
Reporter:	monty solomon	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.7.24	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
In the 5.7.24 release notes there is a warning about the possible failure of some operations on row sizes in compressed tables that are close to the maximum row size.

The warning mentions INSERT operations. Are there any concerns about UPDATE operations?

Is it possible to determine if there will be a problem with existing compressed tables before upgrading to 5.7.24?

How to repeat:
https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-24.html
The zlib library version bundled with MySQL was raised from version 1.2.3 to version 1.2.11. MySQL implements compression with the help of the zlib library.

The zlib compressBound() function in zlib 1.2.11 returns a slightly higher estimate of the buffer size required to compress a given length of bytes than it did in zlib version 1.2.3. The compressBound() function is called by InnoDB functions that determine the maximum row size permitted when creating compressed InnoDB tables or inserting rows into compressed InnoDB tables. As a result, CREATE TABLE ... ROW_FORMAT=COMPRESSED or INSERT operations with row sizes very close to the maximum row size that were successful in earlier releases could now fail.

Hi,

Thank you for your bug report.

As it happens, I know a lot about problems with new zlib version used.

Verified as reported.

Only to add that both UPDATE and REPLACE  are affected.

This is a documentation-only bug, since we do not maintain zlib library.

Posted by developer:
 
The referenced content was revised to include UPDATE statements. 
The documented recommended action to avoid the maximum row size issue is test CREATE TABLE statements for compressed
InnoDB tables with large rows on a MySQL 8.0 test instance prior to upgrading.

Thank you for the bug report.

Thank you, Daniel ......