Bug #24091 ALTER TABLE FORCE referenced, partly implemented, not documented
Submitted: 8 Nov 2006 15:02 Modified: 21 Apr 2011 1:24
Reporter: Magnus Blåudd Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: DDL Severity:S3 (Non-critical)
Version:5.0 and up OS:Any (all)
Assigned to: CPU Architecture:Any

[8 Nov 2006 15:02] Magnus Blåudd 
Description:
There is code in table.cc which print out error message instructiing user to run ALTER TABLE FORCE. Yes, the parser will recognize that command and set a bit in "alter_info->flag" wich will trigger "need_copy_table" and thus a full alter will be done. It's not documented.

How to repeat:
create table t1(a int);
alter table t1;
alter table t1 force;
[8 Nov 2006 15:11] Magnus Blåudd 
ALTER TABLE FORCE is almost identical to what is done by repair table.
[20 Jan 2007 0:00] Bugs System 
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[9 Dec 2009 14:55] Valeriy Kravchuk 
This is still not documented at http://dev.mysql.com/doc/refman/5.1/en/alter-table.html. See bug #49556 also.
[16 Dec 2009 4:08] Paul DuBois 
Still need feedback.
[4 Jan 2010 14:57] Magnus Blåudd 
Checking the code in 5.1.42  show that ALTER TABLE FORCE will set the ALTER_FORCE flags, but there seem to be no code referencing that flag anymore.
[5 Jan 2010 18:17] Valeriy Kravchuk 
So, if ALTER TABLE ... FORCE does nothing as of 5.1.42, let's consider this a server bug and remove it from the code, at least from next GA. Then we can document it as obsolete and doing nothing in current 5.1.x.
[21 Apr 2011 1:24] Paul DuBois 
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.

This was added in 5.0.6 but does nothing. In 5.5.11 it was implemented as an option that causes the table to be rebuilt, as part of the work done for Bug#47205/Bug#11755431. So I will document it in the ALTER TABLE section of the 5.5 manual, but not in earlier manuals.