What is dis-advantages of auto-increment pk

[motofoto]

Hi

Please tell me if you know a dis-advantage of auto-incerment PK

Thanks

[tesuji]

Ah, you again

Did you proceed in understanding EERM?

I call people who put a magical, universal "id" column with an auto-increment on all their tables "id-iots" ! (Joe Celko)

[motofoto]

Ah, you again

Did you proceed in understanding EERM?

I call people who put a magical, universal "id" column with an auto-increment on all their tables "id-iots" ! (Joe Celko)

No I mean that if you design a table like Book which is containing duplicate ISBN(s) for some reason,

and you have the choice between
creating a random unique generated PK from say (Java code)
and
creating an auto incerment Column

What do u choose and why?

I thought you will talk to me about deletion problems or overflow problems regardless of id-iot people.

and I searched about EERM in google, I don't know what is its stands for, I can conclude that you are talking about Relational Modeling but I want to know what that stands for.

Thank you for your time

[peter_budo]

EERM = Extended Entity Relationship Model

I would say auto increment column as if you want to keep track of next item number to be used you need to run extra query to get current number. Plus there are other thing you would have to take care from coding point of view

@tesuji, please drop that joke about "id-iots"