6 calls to db_drop_unique_key() in Drupal 6

system_update_6005 in modules/system/system.install

Add language to url_alias table and modify indexes.

system_update_6019 in modules/system/system.install

Reconcile small differences in the previous, manually created mysql and pgsql schemas so they are the same and can be represented by a single schema structure.

system_update_6032 in modules/system/system.install

profile_fields.name used to be nullable but is part of a unique key and so shouldn't be.

system_update_6043 in modules/system/system.install

Update table indices to make them more rational and useful.

system_update_6044 in modules/system/system.install

RC1 to RC2 index cleanup.

system_update_6055 in modules/system/system.install

Improve indexes on the {url_alias} table.