Starting Over - Clearing your Aliases Completely Or Selectively
Bulk Update All Objects
Older versions of Pathauto (4.7 and 5.x-1) regenerate all aliases of the requested type during a bulk update when the Update action (at Administer > Site Configuration > Pathauto > under General Settings) is set "Create a new alias, replacing the old one."
Bulk update replaces all old aliases with new ones. However, this bulk update created problems, such as incomplete updates and/or server time-outs, for very large sites and/or on particularly slow servers.
Bulk Generate For Non-Aliased Objects Only
As of Pathauto 5.x-2.x or Pathauto 6.x-1.1, bulk update only generates aliases for non-aliased objects - if a node already has an alias, it will not be updated during the bulk update. You might run into problems if you add feed aliases or tracker aliases to an already aliased object. It is best to delete the object's alias and bulk update them.
Deleting all aliases
To regenerate all aliases from a clean slate, Pathauto 5.x-2.x and Pathauto 6.x-1.1 provides a "Delete all aliases" option. You can selectively delete by "all aliases", "users", "content", "user blogs", "vocabularies and terms", and "user trackers".
In Pathauto 5.x-2.x the "Delete all aliases" options can be found at: Administer > Site Building > URL Aliases > under the "Delete all aliases" tab (admin/build/path/delete_all).
In Pathauto 6.x-1.1 the "Delete all aliases" options can be found at: Administer > Site Building > URL Aliases > under the "Delete all aliases" tab (admin/build/path/delete_bulk).
Warning: This will permanently delete aliases from your site. You will not be asked again "are you sure you want to delete all aliases?"
Updating aliases of a certain node type
There is no option within Pathauto for updating only a particular node type, while leaving other nodes untouched. But there is a simple procedure for doing this if you don't have too many nodes you need updating. Works for both Pathauto 5.x-2.x and Pathauto 6.x-1.1.
- Set what you would like done with existing aliases in Pathauto "General Settings":
- Do nothing. Leave the old alias intact.
- Create a new alias. Leave the existing alias functioning.
- Create a new alias. Delete the old alias.
- Create a new alias. Redirect from old alias. (depends on Path Redirect)
- Go to "admin/content/node"
- Filter by content type
- Select all nodes
- Select "Update path alias" from drop down
- Repeat for number of pages you have of that content type
You can also selectively delete aliases by running advanced queries against your database. For example, the following query will delete all node objects:
DELETE FROM url_alias WHERE src LIKE 'node/%';
OR
DELETE FROM url_alias WHERE dst LIKE 'my_custom_pattern/%';
Performing bulk updates in configurable chunks
For sites that need to generate large numbers of aliases or sites that run on slow servers, Pathauto 5.x-2 offers the option to perform bulk updates in configurable chunks - you can specify the number of objects to alias in each bulk update.
Note: if you set the limit to 50 objects per bulk update and have feed aliases enabled, then
100 new aliases should be generated per bulk update (2 aliases per object).
Note: If you are concerned about the effect of bulk update on your site, you should
backup your database (particularly the url_alias table) prior to executing the Bulk update.

Bulk update for PathAuto Drupal 6
Just to clarify the process to bulk update your aliases in PathAuto Dr6, based on my recent experience:
Selectively updating certain patterns
We wanted to change all /films/example style paths to /film/example (basically remove the 's').
Here was the query that worked:
UPDATE url_alias set dst = replace(dst, 'films/', 'film/') WHERE dst LIKE 'films/%';Thank you Jason
-zach
This pattern was very helpful
We had issues with our path for user profiles conflicting with our path for users (since we had both set to be user/----). We used the following query to update the user profile paths:
UPDATE url_alias set dst = replace(dst, 'user/', 'profile/') WHERE dst LIKE 'user/%' and src LIKE 'node/%';(The AND condition was necessary to prevent the paths for users from getting overwritten, also.)
Web Developer,
UrbanMinistry.org
http://www.urbanministry.org/user/evandonovan