Re: [GENERAL] Re: Postgresql OO Patch

>  - the OID (SEQUENCE's) are useless (ok, I say it again and again). Give
>    PostgreSQL the OID and ask PostgreSQL to return the attributes of this
>    object. Perhaps even with class informations !
> 
>    PostgreSQL is not able to do that ! Think about this and you see
>    the usage of the OID in perhaps a different way :-)
> 
>    Therefore: for object system you need complete other types of object
>    identification numbers.

I agree, that's why I have suggested an implied super-class "Object" for
all postgresql objects. Then you could do "SELECT ** FROM object WHERE
oid=?". The ability to place an index over sub-class hierarchies (in
this case oid for all objects) would get the good performance.

>  - query over a hierarchy of classes ! See the example above ! Until
>    you're not able to return multiple sets you get too much garbage or
>    you need to many queries or you need much more disc-space, depending
>    of the way you wrap classes to tables. This feature is a CRITICAL
>    one ! This may push the performance, depending how it is done.

Yep.

>  - for associations (m:n) I still need additional help tables, but
>    that is ok :-)

Actually, postgres can have arrays of oids which is the ODBMS way of
handling associations. Last I looked there are some contrib functions
for doing things like ...

CREATE TABLE foo( bar [] );
CREATE TABLE bar( ... etc);
SELECT bar.** from bar, foo where array_in(bar.oid, foo.bar)  and
foo.oid=?". In other words, to retrieve all the objects in a list.
(forget the actual function name).

>  - no support for tree structures !

AGAIN AGREE! Original postgres had a syntax "SELECT* from foo" to get a
transitive closure on a tree! Why this was removed (argh!) I can only
guess.

>  - more powerful statements DDL to change the structure of a database !

Yep, important.

>  - no support to inform the client about changes inthe database !

Havn't even looked at that.