Bug #14155 MAX_ROWS is wrong on 64bit platform
Submitted: 19 Oct 2005 22:19 Modified: 9 Dec 2005 0:18
Reporter: Peter Zaitsev (Basic Quality Contributor) Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: MyISAM storage engine Severity:S3 (Non-critical)
Version:4.1.14, 5.0.13-rc OS:Linux (Linux 64bit)
Assigned to: Jim Winstead CPU Architecture:Any

[19 Oct 2005 22:19] Peter Zaitsev
Description:
MAX_ROWS are  set wrongs on 64bit Linux if  value is larger than 2^32 

On 32bit version it is just set to 2^32-1,  on 64bit  some strange number is used instead.

Perhaps we should use full 64bit value on 64bit platforms: 

How to repeat:
mysql> create table tmp(i int) max_rows=100000000000;
Query OK, 0 rows affected (0.05 sec)

mysql> show create table tmp;
+-------+----------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                             |
+-------+----------------------------------------------------------------------------------------------------------+
| tmp   | CREATE TABLE `tmp` (
  `i` int(11) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 MAX_ROWS=1215752192 |
+-------+----------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
[20 Oct 2005 5:52] Valeriy Kravchuk
Verified on our nocona server with 4.1.14:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.14

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> create table tmp(i int) max_rows=100000000000;
Query OK, 0 rows affected (0.02 sec)

mysql> show create table tmp;
+-------+----------------------------------------------------------------------------------------------------------+
| Table | Create Table                                   |
+-------+----------------------------------------------------------------------------------------------------------+
| tmp   | CREATE TABLE `tmp` (  `i` int(11) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 MAX_ROWS=1215752192 |
+-------+----------------------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)

mysql> exit
Bye
-bash-2.05b$ uname -a
Linux nocona.mysql.com 2.4.21-32.0.1.ELsmp #1 SMP Tue May 17 17:46:36 EDT 2005 x86_64 x86_64 x86_64 GNU/Linux

The same result was obtained with 5.0.13-rc on nocona.
[27 Oct 2005 0:38] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/31535
[9 Nov 2005 20:05] Barkley Vowk
Please also fix setting the max_rows in alter table, as the supplied patch only addresses max_rows on creation. If the program attempts to tweak max_rows of an existing database, its wrapped at 2^32-1 again.
[9 Nov 2005 22:39] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/32122
[24 Nov 2005 1:01] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/32629
[29 Nov 2005 19:37] Jim Winstead
Fixed in 5.0.17 and 5.1.4.
[9 Dec 2005 0:18] Paul Dubois
Noted in 5.0.17, 5.1.4 changelogs.
[19 Aug 2008 3:24] Golden Liu
I've noticed that in the following patch, you made this change:

-  if (create_info->max_rows > ~(ulong) 0)
-    create_info->max_rows= ~(ulong) 0;
-  if (create_info->min_rows > ~(ulong) 0)
-    create_info->min_rows= ~(ulong) 0;
+  if (create_info->max_rows > UINT_MAX32)
+    create_info->max_rows= UINT_MAX32;
+  if (create_info->min_rows > UINT_MAX32)
+    create_info->min_rows= UINT_MAX32;

(the pack is here: http://lists.mysql.com/internals/32629)

So I still can't set MAX_ROWS bigger than UINT_MAX32, even in a 64-bit system. Why? If I just change the patch to something like this:

-  if (create_info->max_rows > ~(ulong) 0)
-    create_info->max_rows= ~(ulong) 0;
-  if (create_info->min_rows > ~(ulong) 0)
-    create_info->min_rows= ~(ulong) 0;
+  if (create_info->max_rows > UINT_MAX64)
+    create_info->max_rows= UINT_MAX64;
+  if (create_info->min_rows > UINT_MAX64)
+    create_info->min_rows= UINT_MAX64;

Does this fix this bug so we can set MAX_ROWS bigger than UINT_MAX32? 

3x.