- From: Kevin Wiggen <wiggs@xythos.com>
- Date: Sat, 04 Dec 1999 09:23:40 -0800
- To: Jim Davis <jrd3@alum.mit.edu>, www-webdav-dasl@w3.org
I agree with your statements, see my comments: 1. if the client wanted ordering, they would have asked for it. Unlike ordinary WebDAV clients, a DASL client certainly knows about ordering. it may not know about AdvColl ordering, but it does know about ordering in the abstract. so absence of an orderby clause indicates that the client does not want ordering. <KW> OK, I just don't like that in one case we FORCE ordering and in another we IGNORE ordering. I agree with what you are saying about PROPFIND and DASL being different. BUT someone might write a client that only uses DASL. This is easy since PROPFIND is a subset of DASL. It could be weird for this implementer that ordered collections work differently. I can be made to agree that they act differently, I would just like to point out that some people might think its weird (such as me). </KW> 2. I predict that the scope of a DASL search will often be an entire site (or the root collection). i dont think AdvColl style ordering makes sense for the full recursive set of members of a collection, but only for the level 1 members. <KW> True, but nothing is stopping a client from wanting a list of all things in a directory which are NOT images or help text. In this case you can run a DASL query (Depth=1) against a server and make the where clause kick out certain content-types. If this directory is a book (and thus ordered by chapter), the client will most likely want the directory to come back in the correct order. </KW> 3. it may be expensive to compute. a typical implementation of DASL might use a RDBMS to store the properties of resources. The list of rows that match the query may be returned in a random order by the RDBMS. the DASL search arbiter would then have to sort. <KW> DASL needs to have a sort routine on the server. Many things that get sent to DASL might be expensive. I don't see how ordering by one more thing would be that much more expensive than DASL already is. I can ask DASL to order by content-type. Thus the search arbiter would have to sort (or the RDBMS). Either way something needs to know how to sort thus it is no more code, and not more expensive. </KW> 4. I predict that Adv Coll orderings will mostly make sense in the context of having the entire membership of a collection. e.g. when you have a set of pages you want to print in order. I don't think they will always make sense in the context of a random selection of a subset of the collection according to some search criteria. So I doubt the client would care to get this ordering. <KW> I agree with you, but as in my example above, I can give you use cases where it would make sense it DASL </KW> If we FORCE a server to ALWAYS return ordered collection in order in PROPFIND (I am against this too), I think that there should at least be a way of having DASL return by the ordered collection order: Two Ways: 1) If the collection is ordered always add this as the final sort parameter to a DASL query. 2) Create a new DASL tag <d:orderedcollection> for the <d:orderby> clause. In this way, a client can at least ask DASL to sort by the orderedcollection order. I am fine with 2. I think this whole thing is not correct by forcing ordered collections to always return in order during a PROPFIND, BUT if it is, I am ok with number 2 above. BUT I AM NOT HAPPY WITH IT. :) Kevin
Received on Saturday, 4 December 1999 12:25:59 UTC