28def downgrade():
   29    op.alter_column('ps_globals', 'user_agent', type_=sa.String(40))
   30 
   31    if op.get_context().bind.dialect.name != 'mssql':
   32        op.alter_column('ps_contacts', 'id', type_=sa.String(40))
   33    else:
   34        op.drop_constraint('uq_ps_contacts_id', 'ps_contacts')
   35        op.drop_index('ps_contacts_id', 'ps_contacts')
   36        op.alter_column('ps_contacts', 'id', type_=sa.String(40))
   37        op.create_index('ps_contacts_id', 'ps_contacts', ['id'])
   38    op.alter_column('ps_contacts', 'uri', type_=sa.String(40))
   39    op.alter_column('ps_contacts', 'user_agent', type_=sa.String(40))
   40 
   41    op.alter_column('ps_registrations', 'client_uri', type_=sa.String(40))
   42    op.alter_column('ps_registrations', 'server_uri', type_=sa.String(40))