Caros colegas,

Em minha aplicação (que ainda se encontra em desenvolvimento e testes) faço uso de alguns relacionamentos many-to-many e no domínio faço uso das declarações has-many, mapped-by, etc.

Para minha surpresa encontrei um documento que apresenta uma série de "riscos" na utilização destes recursos do Hibernate. 

? “hasMany = [visits: Visit]” creates a Set(org.hibernate.collection.PersistentSet) in Library – the “inverse”
collection in traditional Hibernate
? Adding to the Set requires loading all instances from the database to
guarantee uniqueness, even if you know the new item is unique
? Likewise for a mapped List – Hibernate pulls the entire collection to
maintain the correct order, even if you're adding to the end of the list
? In traditional Hibernate you could map the collection as a Bag, which
is just a regular Collection with no ordering or uniqueness guarantees,
but Grails doesn't support Bags

Espantou-me bastante o fato que Adding to the Set requires loading all instances from the database to
guarantee uniqueness, even if you know the new item is unique.

e também:

Works fine in development when you only have a few Visits, butimagine when you deploy to production and you have 1,000,000 Visits
and want to add one more

Isto é verdade? Vocês já passaram por estes problemas?

Referência: http://burtbeckwith.com/blog/files/169/gorm%20grails%20meetup%20presentation.pdf?


Obrigado!