2008/6/25 Evgeny Egorochkin <[EMAIL PROTECTED]>: > В сообщении от Wednesday 25 June 2008 10:36:41 Mikkel Kamstrup Erlandsen > написал(а): >> 2008/6/24 Evgeny Egorochkin <[EMAIL PROTECTED]>: >> > В сообщении от Tuesday 24 June 2008 16:05:54 Mikkel Kamstrup Erlandsen >> > >> > написал(а): >> >> 2008/6/24 Mikkel Kamstrup Erlandsen <[EMAIL PROTECTED]>: >> >> > 2008/6/13 Mikkel Kamstrup Erlandsen <[EMAIL PROTECTED]>: >> >> >> 2008/6/13 Jos van den Oever <[EMAIL PROTECTED]>: >> >> >>> 2008/6/13 Urho Konttori <[EMAIL PROTECTED]>: >> >> >>> > We have been evaluating the Xesam for multiple uses at Nokia and >> >> >>> > one of them is media player use. In many cases, where all the >> >> >>> > songs need to be listed, they need to be listed with three sorting >> >> >>> > criteria: Artist, Album, Track#. Xesam provides only two sorting >> >> >>> > criteria. Now, you might argue that the application should do the >> >> >>> > tertiary sorting, but then if we say that, then why two sorting >> >> >>> > criteria, or one? >> >> >>> > >> >> >>> > I'm quite sure this is not the only use case where tertiary >> >> >>> > sorting (or even more) would be beneficial. >> >> >>> > >> >> >>> > Also, the API looks a bit glued when you have primary and >> >> >>> > secondary sorting as the session properties. Why not instead >> >> >>> > change it to an array of sort criteria? So, as to call it just >> >> >>> > sort.fields? >> >> >>> > >> >> >>> > It would be very good if this sort of change could still be done >> >> >>> > to the xesam 1.0 spec, either next to the current primary and >> >> >>> > secondary sorting, or better yet, as the only way to set the sort >> >> >>> > order. It would be much cleaner way to do it. >> >> >>> > >> >> >>> > Anyway, I'm looking forward to comments on the subject. >> >> >>> >> >> >>> I agree with your suggestion. >> >> >>> We would also need a way for the server to specify what type of >> >> >>> sorting it supports. >> >> >>> For example a readonly property: sortableFields and a property that >> >> >>> says how many sorting fields can be used. >> >> >>> Some servers may not support sorting at all (grep) or allow only >> >> >>> sorting on one field. >> >> >> >> >> >> I am also for this, although I think it is quite a big feature >> >> >> compared to our current freeze level. >> >> >> >> >> >> It is a good point you raise Jos. I do however think that it might be >> >> >> acceptable to require the servers to be able to sort the hit data. >> >> >> Otherwise one might have to pull massive amounts of hits over the >> >> >> wire only to get those with the highest atime at the top. >> >> > >> >> > Consider this thread bumped. It is our list of blockers I recently >> >> > posted about. We need a clear decision. >> >> > >> >> > I already made my point above. >> >> >> >> There has been some discussion on this on IRC which have led me to >> >> believe that the following solution would be optimal for all: >> >> >> >> * Scrap sort.primary and sort.secondary. >> >> >> >> * Introduce three new session properties: >> >> >> >> - sort.fields a read/write list of fields to sort after, in that >> >> order. Default value ['xesam:relevancyRating']. The server should >> >> truncate this list to to the size specified in vendor.maxSortFields if >> >> too many sort fields are requested >> >> >> >> - vendor.sort.maxfields a readonly uint. Specifies how many fields >> >> in sort.fields will be taken into account, as mentioned, sort.fields >> >> should be truncated at this length. This property must be 1 at >> >> minimum. If this value is 0 any number of fields can be used. Default >> >> value is undefined. >> >> >> >> - vendor.sort.fields a readonly list of strings naming all fields the >> >> server can sort after. If this list is empty all known fields can be >> >> used for sorting. Default value is []. >> > >> > This parameter is superfluous. Suppose a client app determines the server >> > doesn't support sorting by required field. Either app has to do sorting >> > and doesn't really care about server sorting capabilities. If app doesn't >> > implement sorting, then the server can ignore fields it can't sort on and >> > that's all that can be done. >> > >> > Maybe there's another use case where app needs to know if server did sort >> > or not... I can't think of one atm. >> >> Consider this: A paged client showing 20 hits/page. If xesam:title is >> in vendor.sort.fields we make the list headers clickable so that the >> user can sort hits alphabetically by title. Combining this case with a >> result set of 50.000 hits should clear out the use case I think, I >> would rather not pull in 50.000 hits and sort them if I can avoid it >> (consider a grep-like or web-based server - although they may have >> problems in any case). Or maybe there is a clever way around this that >> I can not see..? > > Clickable column argument does sound sane. > > More likely than not we're going to see backends that don't sort at all like > grep or db-driven backends that can sort all you want. The only possible gray > area here are web services wrappers written by community... The services are > very much likely running on top of a plain filesystem with no sorting or a > db, but will they expose sufficient sorting capabilities?
Well. Lucene is also in a semi-gray area since it requires the fields to be indexed to sort on them... I don't know about Xapian... Cheers, Mikkel _______________________________________________ Xesam mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/xesam
