Re: Persistence

frebe73@xxxxxxxxx wrote:
In the OO world, people often claim that they use a SQL database "for
persistence". Mostly I think that the person making that claim actually
uses other features - like transactions, integrity, queries, etc - and
just use the word persistence because it's a buzzword. But sometimes
there are people that claims that only the persistence features of a
SQL database should be used or that a SQL database does not provide any
other features but persistence.

What are the opinitions at comp.object?
1. A SQL database provides many other features but persistence and they
should be used. The use of the word persistence is just used in a
routine manner and is not a correct description of what we use a SQL
database for.

I use "persistence" to signify saving and loading of otherwise memory
bound objects to permanent storage thereby allowing them to live longer
than the OO program. I have also encountered the phrase "object IO" to
mean the same thing but not at this NG.

It is object storage from an OOP perspective. There is also
serialization, which isn't just another buzzword for the sake of it, it
refers to a different kind of object IO.

2. A SQL database provide many other features but persistence, but the
persistence feature is the only thing that should be used.

The relational model (RM) and RDBMS have strengths and features of
their own, which should not be overlooked.

3. A SQL database does only provide persistence features.

I think the opposite, I think the RM has next to no support for object
persistence.

The relational model represents data in one and only one way, as a set
of tuples in relations where each tuple contains a set of attributes.
There is no direct support of object storage and subsequent
instantiation of objects from disk storage. That's why some people have
trouble mapping from OOP to the RM. I suppose if they understood both
technologies better they'd have less trouble because there are
relatively easy ways to do it.

4. Something else.

Fredrik Bertilsson
http://frebe.php0h.com

Cheers.

.

Relevant Pages

  • Re: SQL
    ... >> If we ignore the persistence aspect, what remains is the organization of ... >Here are my top four non-persistence related features that I use every ... Those I'd generally consider to be part of the relational model - the ... you have any examples of relational databases that have specific features ...
    (comp.object)
  • Re: Persistence
    ... If you have such features ... Persistence is strictly about object IO. ... The relational model has nothing to do with disk storage. ...
    (comp.object)
  • Re: SQL
    ... persistence is one of MANY features of a DB. ... > or less) to the relational model, and and it does so in a persistent ... >>> databases. ...
    (comp.object)
  • Re: Persistence
    ... If you have such features ... Persistence is strictly about object IO. ... There is no direct support of object storage and subsequent ... instantiation of objects from disk storage. ...
    (comp.object)
  • Re: Relational database & OO
    ... data to a persistence storage medium. ... using the features already provided by the RDBMS, ... Caching is the second issue. ...
    (comp.object)