MySQL Bugs: #72980: Workbench unable to fetch tables over slower connection

Bug #72980	Workbench unable to fetch tables over slower connection
Submitted:	12 Jun 2014 7:44	Modified:	24 Jul 2014 8:15
Reporter:	IGG t	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Workbench	Severity:	S3 (Non-critical)
Version:	6.1.6.11834 build 1642	OS:	Windows (Windows 7)
Assigned to:		CPU Architecture:	Any

Description:
When opening a connection to a database over a slow connection (VPN to our remote site in another country), it displays the schemas OK, but when I try to show the tables / views / procedured etc. it tries for about two seconds to fetch them before reporting 'tables could not be fetched'.

Accessing a local database works fine.

If I use MySQL Query Browser it takes about 45 seconds, but does then display the table names.

If I manually type in the query then it runs fine.
If I type SHOW CREATE TABLE xxx then it works fine.

In the Preferences > SQL Editor I have the two timeouts (DBMS Connection Keep Alive and DBMS Connection Read Time Out) set at 600.

How to repeat:
Open a connection to a database over a slow connection, and then try to display table names.

- - - 
01/07/2014
I've now had the same problem on a database on our local network, suggesting the issue isn't to do with the database being remote.

I have found that when trying to display the tables, I am getting:
Error loading schema content	
Error Code: 1548 Cannot load from mysql.proc. The table is probably corrupted	

This presumably is the cause of the issue. I'm assuming there is a difference between the way Query Browser and Workbench work in this resepct, as it works fine in Query Browser.

Are you using WorkBench against which server version. If you did and upgrade of the server you applied mysql_upgrade?. Thanks.

The servers are all 5.5.36, installed on windows 2008 R2. They are set up as slave databases, and would have been copied from another 5.5 database.
I didn't run mysql_upgrade as they were copied from a database of a similar version.

I have managed to fix the problem. It turns out that on some of my databases one of the fields in mysql.proc had a different datatype.

Running:
ALTER TABLE `mysql`.`proc` MODIFY COLUMN `comment` TEXT CHARACTER SET utf8 COLLATE utf8_bin NOT NULL;

has fixed the problem.