Bug #80794 MEMORYengine memory usage
Submitted: 18 Mar 2016 18:02 Modified: 4 Apr 2016 17:12
Reporter: Derek Downey Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:5.7 OS:Any
Assigned to: CPU Architecture:Any
Tags: Memory

[18 Mar 2016 18:02] Derek Downey
Recently the MySQL documentation for how MySQL utilizes memory was updated: http://dev.mysql.com/doc/refman/5.7/en/memory-use.html

One omission is regarding MEMORY storage engines. 

There is a link to the internal temporary tables (http://dev.mysql.com/doc/refman/5.7/en/internal-temporary-tables.html), which describes the how explicit MEMORY engine tables behave:

"This differs from MEMORY tables explicitly created with CREATE TABLE: For such tables, only the max_heap_table_size system variable determines how large the table is permitted to grow and there is no conversion to on-disk format."

But the 'memory-use' documentation should explicitly indicate this.

How to repeat:

Suggested fix:
Update documentation for how mysql uses memory to include explicit MEMORY engine tables.
[18 Mar 2016 21:20] MySQL Verification Team
Thank you for the bug report.
[4 Apr 2016 17:12] Daniel Price
Posted by developer:
The documentation has been updated as requested. The change should appear online within 24 hours.

Thank you for the bug report.