alter table acs_data_links add column relation_tag varchar(100);

create index acs_data_links_rel_tag_idx on acs_data_links (relation_tag);

alter table acs_data_links drop constraint acs_data_links_un;

alter table acs_data_links add constraint acs_data_links_un unique 
(object_id_one, object_id_two, relation_tag);

alter table apm_package_dependencies drop constraint apm_package_deps_type_ck;
alter table apm_package_dependencies add
  constraint apm_package_deps_type_ck
  check (dependency_type in ('provides', 'requires', 'extends', 'embeds'));