MySQL Bugs: #55866: Workbench freezes when changing default schema while table list is retrieved

Bug #55866	Workbench freezes when changing default schema while table list is retrieved
Submitted:	9 Aug 2010 21:49	Modified:	6 Feb 2013 21:14
Reporter:	Matthew Hall	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Workbench: SQL Editor	Severity:	S3 (Non-critical)
Version:	5.2.26	OS:	MacOS (10.6.4)
Assigned to:		CPU Architecture:	Any
Tags:	freeze, hang, sql editor

Description:
When selecting a new "Default:" schema in SQL editor, MySQL Workbench hangs until the table/view/routine list is retrieved and updated in the "Overview" tab.  This can be very annoying when working with schema with a high table count or a server with very slow performance.

I'm not sure what it does on other platforms, but on OS X, I get a rainbow pinwheel until the schema details for my newly selected default are retrieved.  It appears to be related to populating the "Overview" tab with the schema's details, as the same behavior can be reproduced by clicking the "Refresh the Schema List" button.

I should note that this behavior does not happen when changing the default schema with a SQL "use [schema]" statement.

How to repeat:
1. Open SQL editor connected to a MySQL instance with many large (lots of tables, views, procedures) databases.
2. Change the "Default:" schema using the combo box above the list of available schema.
3. Observe that MySQL hangs until the list of tables/view/procedures is retrieved and rendered in the "Overview" tab.

Suggested fix:
Change the behavior so that Workbench doesn't hang while doing this operation.

I should also note that this behavior also manifests itself in MySQL Workbench hanging when initially opening an SQL Editor.  If server performance is slow, or the last (alphabetically) schema on the server is large (many tables/views/procedures), Workbench hangs while populating the "Overview" tab, as the last (alphabetically) schema on the server is selected by default.

Please look into general log and try to do the comments by using CLI.

Is that as slow?

I'm not sure where the "general log" for Workbench is under OS X.  If you can direct me to its location, it would help me provide the additional information you've requested.  Thanks!

You misunderstood me. I meant general log from your server not from Workbench.

Log of connecting and changing schema from workbench

Attachment: mysql.log (application/octet-stream, text), 6.09 KiB.

The "SELECT 'table'" queries in that log all take just shy of 10 seconds to return results (about 450 rows describe our schema) when running mysql from the command line on the server machine.  Our databases don't have many views or routines, so those don't take as long.  MySQL Workbench does hang for 20-30 seconds any time it requests that information.

as workaround, you can disable the overview panel in preferences to increase response time of Workbench when switching between larger schemas

Closing old bug as the new UI is no longer affected by this