MySQL Bugs: #41954: Values set for "sort_buffer_size" are rounded to other values.

Bug #41954	Values set for "sort_buffer_size" are rounded to other values.
Submitted:	8 Jan 2009 10:21	Modified:	12 Jan 2009 16:13
Reporter:	Horst Hunger	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.1	OS:	Any
Assigned to:	Paul DuBois	CPU Architecture:	Any

Description:
Values set for "sort_buffer_size" are rounded to other values, which is not described in the user manual. These rounded values depend on the platform.
That is also valid for other system variables specifying buffer sizes.

How to repeat:
run test "sort_buffer_size_basic_32.test".

Suggested fix:
description of the platform depoending rules of rounding the values of the system variables.

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.

We will cover this case with a general statement in the system variable section:

      Some system variables control the size of buffers or caches. For a
      given buffer, the server might need to allocate internal data
      structures. These structures typically are allocated from the
      total memory allocated to the buffer, and the amount of space
      required might be platform dependent. This means that when you
      assign a value to a system variable that controls a buffer size,
      the amount of space actually available might differ from the value
      assigned. In some cases, the amount might be less than the value
      assigned. It is also possible that the server will adjust a value
      upward. For example, if you assign a value of 0 to a variable for
      which the minimal value is 1024, the server will set the value to
      1024.