MySQL Bugs: #68405: Length encoded integer defines overlapping intervals for 2 / 3 byte ints.

Bug #68405	Length encoded integer defines overlapping intervals for 2 / 3 byte ints.
Submitted:	16 Feb 2013 22:57	Modified:	4 Mar 2013 16:59
Reporter:	Roland Bouman	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:		OS:	Any
Assigned to:	Paul DuBois	CPU Architecture:	Any

Description:
At http://dev.mysql.com/doc/internals/en/overview.html#length-encoded-integer it reads:

* if the value is >= 251 and < (2^16), it is stored as fc + 2-byte integer
* if the value is >= (2^16-1) and < (2^24), it is stored as fd + 3-byte integer

If this were true, than a value of 2^16-1 would fall in both these categories, since 2^16-1 is less than 2^16 (upper boundary of 2 byte int) and is also equal to 2^16 -1 (documented lower boundary of 3 byte int).

It seems to me it should read:

* if the value is >= (2^16) and < (2^24), it is stored as fd + 3-byte integer

How to repeat:
Read doc. Observe problem described above.

Suggested fix:
Correct doc. Fix problem described above.

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.