Talk:Hierarchical model

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Can anyone tell me what the 'restrictions' actually are?

Contents 1 Reason for {{Cleanup}} 2 LDAP 3 Mistake? 4 You say Data, I say Datum 5 Adabas not hierarchical 6 A bit narrow

[edit] Reason for {{Cleanup}}

The text doesn't reflect the lemma: Hierarchical model should describe the logical elements only, but the introduction for example talks about database management systems. --S.K. 17:39, 24 Jun 2005 (UTC)

Agreed - for definite the current 'definition' includes elements that are clearly descriptions of relational database models, rather than hierarchical models, and are therefore inaccurate/incorrect. Unfortunately I don't have a complete and reliable alternative definition for you.

Also - Isn't Adabas a relational database?

G.R.P, Wilts, 2nd May 06

According to Software AG's Adabase site Adabase D is 'a database system that fully implements the relational model'. Apparently not all versions of Adabase are relational.

K.K.S. July 17, 2006

[edit] LDAP

Is LDAP considered to follow the hierarchical model?

From the LDAP article:

LDAP directory entries feature a hierarchical structure that reflects political, geographic, and/or organizational boundaries. In the original X.500 model, entries representing countries appear at the top of the tree; below them come entries representing states or national organizations. Typical LDAP deployments use DNS names for structuring the top levels of the hierarchy. Further below might appear entries representing people, organizational units, printers, documents, or just about anything else.

[edit] Mistake?

but each child only has two parents

Doesn't each child only have one parent??? —The preceding unsigned comment was added by 83.65.35.100 (talk) 12:37, 12 January 2007 (UTC).

Yes- this is a mistake. Alex Jackl 15:41, 25 March 2007 (UTC)

Maybe the example about child records should not be about human children, as they usually do have two parents, both of whom may be employees. (Peter) —Preceding unsigned comment added by 193.226.212.139 (talk) 14:10, August 30, 2007 (UTC)

[edit] You say Data, I say Datum

I replaced the pluralization of data in the intro paragraph because data is still considered officially to be a plural noun. I do appreciate though that it is creeping into common usage to treat it as a singular collective noun. i believe in the end that may even win over but it is currnetly incorrect to tlak about "Data is". It should be "Data are". See Data. Alex Jackl 15:41, 25 March 2007 (UTC)

[edit] Adabas not hierarchical

It's partially-inverted list - I used to work for them. I'm deleting the list item.Philcha 22:06, 19 October 2007 (UTC)

[edit] A bit narrow

There are other kinds of hierarchical models, for example the hierarchical statistical models used in Bayesian data analysis. These should be mentioned.

Also a tree structure is a bit limiting. Yes there are higher and lower levels in the hierarchy, but the structure needn't be a tree. Look at organisation charts, a kind of hierarchical model; there are usually plenty of dotted lines as well as the conventional parent-child relations.

--84.9.67.105 (talk) 09:31, 11 April 2008 (UTC)