On Mon, Nov 10, 2014 at 12:03 PM, Eduard Moraru <[email protected]> wrote: > Hi Marius, > > On Mon, Nov 10, 2014 at 12:24 PM, Marius Dumitru Florea < > [email protected]> wrote: > >> I'm undecided. As a technical Linux user I prefer case sensitivity, but I >> can see why this is sometimes unexpected for non-technical users. I'm not >> sure how you plan to implement this. I know this thread is not about the >> technical aspects but still I think it's important to consider the cost >> that this change will imply. >> >> First, even for a case insensitive system, I think it's very important to >> preserve the case entered by the user. For instance, If I create a user >> with the alias 'myCoolAlias' then I wouldn't like to see 'mycoolalias' >> displayed in the UI. Same, if I attach a file named >> 'myCoolPresentation.odp' then I want to see precisely that name on the list >> of attachments. So we need to store case sensitive values in the database. >> > The difference from now will be: >> >> * when creating an entity: check that there's no other entity that has the >> same normalized reference (toLowerCase/toUpperCase) >> >> * when retrieving an entity: look for normalized references >> >> This means we'll have to call toLowerCase/toUpperCase very often so we need >> proper database indexes. Otherwise we'll have a performance impact. >> > > Right. I posted a similar comment on the Jira issue. > > Another interesting idea I was just thinking about would be to add > uniqueness constraints in the database on lower(doc.fullName) for instance. > That would cover the creation step. > > Regarding performance, I have found in some quick searches that uniqueness > constraints are also achievable through unique function-based indexes [1]. > > On both cases, we would have to investigate on the database support or > solutions for using a function like lower() for the database unique > constraint or the unique index. > > ---------- > [1] > http://stackoverflow.com/questions/3944840/create-unqiue-case-insensitive-constraint-on-two-varchar-fields > > >> Second, we have lots of places that query the database and since we have to >> store the raw case-sensitive values then we need to update all this places. >> Moreover, since it's not about a single field/column I'm not sure we can >> write a query filter to lower the case automatically. Then we also have a >> lot of extensions that query the database and that create entities. Those >> will have to be updated too. >> > > Not sure a filter would be the solution, since queries should be > application-specific. > > >> >> Lastly, AFAIK lower case and upper case are locale dependent. The 'lower' >> query function doesn't have a locale parameter so it depends on the locale >> the database has been configured with. So there can be cases when a user >> won't be able to retrieve an entity using some locale dependent lowercase >> version of the reference because the database computes the lower case >> differently than what the user expects (because it uses a different >> locale). >> > > Well, as long as we do something like lower(myValue) = lower(dbValue) > instead of myValue = lower(dbValue), we should be good, right? (i. e. apply > the same databse collation/logic on both the searched value and the db > value so that we never get a missmatch).
Not really, the problem you will have is that lower is not going to do it's job because you are not in the right locale. That means that you might end up with the request thinking that two values are not equals while if lower did its job properly it would have been. In XWiki side we will apply the locale to String.toLower and we will get a different result which means that you have cases where in the require two document name are not equals but they are when you compare two DocumentReference which might create many issues. > > Thanks, > Eduard > > >> >> Thanks, >> >> Marius >> >> >> On Nov 7, 2014 12:34 PM, "Eduard Moraru" <[email protected]> wrote: >> > >> > Hi users and devs, >> > >> > I would like to have your opinion on the topic of case sensitive vs case >> > insensitive and which one you prefer in XWiki. >> > >> > Currently, XWiki is case sensitive. This means the same resource name >> > (document name, space name, etc) can be written with either small letters >> > or big letters or a mix. >> > >> > Examples: You can have both "Main.Test" and "Main.test" as 2 different >> > documents. Also, you can have "XWiki.Admin" and "XWiki.admin" as 2 >> > different users. This also applies to URLs, as "/Main/Test" is different >> > from "/Main/test" or "/main/test", so all these 3 are different >> resources. >> > >> > Even from this short description, one can already identify possible >> > problems of this approach. >> > >> > From the top 3 operating systems (Linux, Mac an Windows), only Linux is >> > case sensitive, the other two (more user-focused Operating Systems) are >> > both case insensitive. >> > >> > Since XWiki has one of its main targets the Enterprise users, it is safe >> to >> > assume that the correct approach would be to also be more user-focused >> and >> > simplify things and avoid confusions by being case insensitive as well. >> > >> > Also, a quick search on existing issues validates the need for this >> > improvement: >> > http://jira.xwiki.org/issues/?jql=text%20~%20%22case%20insensitive%22 >> > >> > What do you think? Is it OK to keep XWiki case sensitive, or would you >> > prefer it case insensitive? Bring arguments. >> > >> > I have also created a jira issue for this idea: >> > http://jira.xwiki.org/browse/XWIKI-11412 to track it in the future. >> > >> > Thanks, >> > Eduard >> > _______________________________________________ >> > devs mailing list >> > [email protected] >> > http://lists.xwiki.org/mailman/listinfo/devs >> _______________________________________________ >> devs mailing list >> [email protected] >> http://lists.xwiki.org/mailman/listinfo/devs >> > _______________________________________________ > devs mailing list > [email protected] > http://lists.xwiki.org/mailman/listinfo/devs -- Thomas Mortagne _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
