mysql - Intersection tables or Common Super table -


i have design so. there tables each object class. each table contains rows (objects) needs associated multiple statuses.

statuses table

  • id
  • status

users

  • id
  • username
  • ...

some other object class

  • id

  • ...

what's best way link each object class table status table? tossing between 2 methods described in sql antipatterns:

intersection tables

users_has_statuses

  • user_id
  • status_id
  • unique(user_id, status_id)

etc. require intersection table each object class. so, add more object classes (tables), need add intersection table, means that

ancestor tables

object_ancestor

  • id

object_ancestor_statuses

  • object_ancestor_id
  • status_id
  • unique(object_ancestor_id, status_id)

each object class have column foreign key linked id column in object_ancestor table.

in terms of performance , design elegance, way better?

my opinion intersection tables way better.

if have many tables entities statuses , use single table linking them statuses, add more , more data, performance increasingly degrade (because when dbms statuses of entity, have "go through" entries other types of entities).

problem ancestor way looking @ database structure, couldn't tell types of entities have statuses. if have people, dogs , rocks, each having entries in ancestor table, couldn't tell rocks don't have statuses, example.


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