7 calls to db_add_primary_key() in Drupal 6

system_update_6001 in modules/system/system.install

Add version id column to {term_node} to allow taxonomy module to use revisions.

system_update_6002 in modules/system/system.install

Increase the maximum length of variable names from 48 to 128.

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_6022 in modules/system/system.install

Update files tables to associate files to a uid by default instead of a nid. Rename file_revisions to upload since it should only be used by the upload module used by upload to link files to nodes.

system_update_6033 in modules/system/system.install

Change node_comment_statistics to be not autoincrement.

system_update_6043 in modules/system/system.install

Update table indices to make them more rational and useful.

_db_create_keys in includes/database.pgsql.inc