Re: [Engine-devel] Move SQL out of stored procedures
On 03/26/2013 07:39 PM, Alon Bar-Lev wrote:
----- Original Message -----
> From: "Juan Hernandez" <jhernand(a)redhat.com>
> To: engine-devel(a)ovirt.org
> Sent: Tuesday, March 26, 2013 7:34:04 PM
> Subject: [Engine-devel] Move SQL out of stored procedures
>
> Hello,
>
> I would like to start a discussion about the subject. I think this is
> something we need to do if one day we want to be able to use any
> database other than PostgreSQL.
Hello,
I think that database layer is a software interface like any other software interface, if
done properly, a dba can convert the stored procedure to any other database without any
code change.
You probably mean "any other database that supports stored procedures",
which is not the same that "any other database".
It is very clear what is the interface of a relational database: a set
of relations with a set of restrictions.
This way the database specific implementation lives within the
database and maintained by the designated dba.
I don't now exactly what you mean by "dba", but if you mean "database
administrator" I really don't see typical database administrators
rewriting stored procedures provided by a product to suite their own
database management system.
Maybe by "dba" you mean "the developer of the persistence layer". Will
your proposal be maintaining different sets of stored procedures,
written in different languages for different database management systems?
Fixups and optimizations can be done in database without touching the
code.
Seems that you think that stored procedures aren't "code". What are they
then?
Backward compatibility layer is much simpler to implement based on
stored procedures than complex set of views and tables.
Also, accessing the database via different technologies is simpler if there is maintained
database interface (stored procedures).
It also means that you make the database a procedural system, and it
shouldn't be. A database should not contain logic, only data. Logic
changes quite frequently and data needs to survive for a long long time.
I've seen hibernate based java applications that promised to be
database independent but at the edges when performance counts, the DAO became HQL, then a
special dialect and finally database specific SQLS.
I've seen exactly the opposite, if that matters.
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