I'm thinking about starting a hobby project.
I wrote a files-based Bulletin Board years ago.
I'd like to convert it to a more database-like system, so
password-identified users could edit old posts.

Forums are inherently hierarchical and hierarchies are
tough with relations. I have modeled relational hierarchies in
the past, with what Joe Celko calls "path enumeration."
That works, but it's a bit ugly and making indexes on loooong
path-strings that all start off the same way is messy.

I'd rather work directly with hierarchies: with XML.
For native XML processing you can work with SleepyCat,
Exist or even Xindice (or expensive proprietary products
like Mark Logic or Ipedo).

But Oracle and Postgres have a way to stuff XML blobs
into a column now, and also a way to query with XPath
over those XML blobs

The native XML databases (SleepyCat etc) all require running a tomcat
server, while postgres is a bit easier to setup and install.

PUNCHLINE QUESTION, sort of.
I've worked with SleepyCat, Exist and Tomcat.
It's pretty powerful stuff and it has a lot to offer.
Mapping between GUI and data is oh so easy with
hierarchies, compared to relations. But what about
performance? I've never worked with Oracle/Postgres
XML XPath querying. And I've heard rumors it's dog slow
above a certain size/traffic threshold.
Any comments? Anybody done much with Postgres/XML?
Have any comparisons to SleepyCat?

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!

salmobytes wrote:
....
Suggest that it is more accurate to say that forums are typically
implemented with hierarchical techniques. It would be even more
accurate to say that forums are inherently ordered, eg., by date & time
within topic. I don't know what a relational hierarchy could be, but
for sure the RM is not concerned with ordering. I suspect you are not
talking about real hierarchies but rather about graphical presentation
techniques, about which the RM has nothing to say.


The forums I see are concerned with messages but not message content,
whereas it is the readers who are concerned with message content, eg.,
it is the audience who operate on the content, not the system. I think
you are talking about using the RM for physical storage, implying that
you don't need its inference ability and in the same breath saying that
it is ponderous to use the RM to implement ordering. Well, if that's
what you mean, yes it is ponderous to use the RM to implement ordering
because the RM doesn't support ordering in the first place!