Hi Fabio, thanks again for your answer. What you say comes handy, I will work that way.
I am creating the db using Nhibernate, and everything is working fine, but deletion, which actually works, it just takes a long time, since is not doing one shot deletions. I am going to try using "on-delete="cascade" and if it doesn't work well I can try the second approach you mention. Anyway in my previous mail, my question was not regarding this 2 methods, because I havent tested them yet. Was regarding using what is recomended on the documention: 18.5.4. One shot deleteThat is not very clear, it says that by clearing the collection of elements, the items should be deleted in one shot ( list.Clear()) And it mentions: one-shot-delete apply to collections mapped inverse="true". That is the first answer I got, and I tried to implement it and it didn't work, from what Roger says, and what i could see on internet, actually putting inverse="true" won't allow it work. So i am not sure if I am not understanding the documentation, or maybe it is wrong. Regards, Dzy.- On Mon, Apr 4, 2011 at 6:21 PM, Fabio Maulo <[email protected]> wrote: > ehm... are you creating the DB using NH ? > are you validating the schema using NH ? > on-delete="cascade" works as espected but you have to check what NH think > you have in the DB with what you really have; > also you have to check the <cascade> configuration because even when you > have the ON DELETE constraint (hard cascade) the delete operation may become > "inefficient" due soft-cascade (logic cascade). > in practice... if you have on-delete="cascade" and you are 100% that the > child entity does not have any other soft-cascade with others entities, on > delete, be sure that your <cascade> value does not includes neither "delete" > nor "delete-orphans". > > btw > session.CreateQuery("from Child c where c.Parent.Id = > :theParent").ExecuteUpdate(); > do the same work you done with Ado.NET > > On Mon, Apr 4, 2011 at 5:45 PM, Dzyann Leleur <[email protected]> wrote: > >> Hi Roger, thanks for your answer. >> >> That the parent know its children so far has been relevant for the >> deletion case, which is needed. Now i do Understand if you guys consider >> this shouldn't be handled by Nhibernate. That is why I sent an email here. I >> have all the Web Application working with Nhibernate, and when I found this >> problem, the easiest solution for me was just to use ado.net, that is why >> in my initial email I asked if the best would be an approach like just do >> the sql sentence (ado.net or such). >> I asked help here because I wanted to try keep all the application using >> Nhibernate, but if for cases like this doesn't make sense, is fine. >> >> I read what you said about the inverse=true, but I have certain confusion >> with it. >> On the link you gave me ( >> http://www.nhforge.org/doc/nh/en/index.html#performance-collections-oneshotdelete) >> says: >> one-shot-delete apply to collections mapped inverse="true". >> >> Now from what I have been reading on internet this doesn't work, It >> actually behaves like you say. So maybe the documentation is wrong? or i >> just totally misunderstood what it says? >> >> Regards, >> >> Dzy.- >> >> >> >> On Mon, Apr 4, 2011 at 4:52 PM, Roger Kratz <[email protected]>wrote: >> >>> <<I am not going to perform operations like you put, for each item of the >>> collection, we are just doing queries over them.>> >>> >>> Instead of letting the parent knows thousands of children, isn't enough >>> if the child knows its parent? >>> >>> >>> Anyhow.... >>> >>> Having inverse=true means that this side doesn't own the collection. >>> AFAIK, this means that theCollection.Clear() won't do anything from a NH >>> perspective. >>> >>> Try hql delete, plain ado.net or, as already mentioned, >>> on-delete="cascade". >>> >>> >>> >>> ________________________________ >>> Från: [email protected] [[email protected]] för Dzyann >>> Leleur [[email protected]] >>> Skickat: den 4 april 2011 20:04 >>> Till: [email protected] >>> Ämne: Re: [nhusers] Delete Cascade taking a long time >>> >>> Hi, >>> The Domain, is designed as it is, is a very specific case, that doesn't >>> happen much. And actually, is just an applicatin to migrate data, so the >>> user doesn't have this problem of having such massive associations. >>> >>> I am not going to perform operations like you put, for each item of the >>> collection, we are just doing queries over them. >>> >>> What I want to know if the way I set the deletion was correct. >>> This is what i have (without the on-delete="cascade") >>> >>> <hibernate-mapping xmlns="urn:nhibernate-mapping- >>> 2.2" default-access="property" auto-import="true" default-cascade="none" >>> default-lazy="true"> >>> <class xmlns="urn:nhibernate-mapping-2.2" mutable="true" name="Query, >>> Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" >>> table="`Query`"> >>> <id name="Id" type="System.Int32, mscorlib, Version=4.0.0.0, >>> Culture=neutral, PublicKeyToken=b77a5c561934e089"> >>> <column name="Id" /> >>> <generator class="identity" /> >>> </id> >>> <bag cascade="all-delete-orphan" inverse="true" name="NasLocations" >>> mutable="true"> >>> <key> >>> <column name="Query_id" /> >>> </key> >>> <one-to-many class="NASLocation, Domain, Version=1.0.0.0, >>> Culture=neutral, PublicKeyToken=null" /> >>> </bag> >>> <bag cascade="all-delete-orphan" inverse="true" name="MetadataItems" >>> mutable="true"> >>> <key> >>> <column name="Query_id" /> >>> </key> >>> <one-to-many class="MetadataItem, Domain, Version=1.0.0.0, >>> Culture=neutral, PublicKeyToken=null" /> >>> </bag> >>> >>> Mapping for QueryMetadataItem and NasLocations relation with Query: >>> >>> <many-to-one class="Query,Domain, Version=1.0.0.0, Culture=neutral, >>> PublicKeyToken=null" foreign-key="Query_id" name="Query"> >>> <column name="Query_id" /> >>> </many-to-one> >>> >>> I am deleting the items as follows: >>> query.NasLocations.Clear(); >>> query.MetadataItems.Clear(); >>> >>> And then removing the Query itself. >>> The NasLocations items do not get deleted at all, and the MetadataItems >>> get delete one by one. >>> >>> I did this following the link Roger gave me. I don't see what I am doing >>> wrong. >>> >>> Regards, >>> >>> Dzy.- >>> >>> >>> On Mon, Apr 4, 2011 at 2:48 PM, Fabio Maulo <[email protected] >>> <mailto:[email protected]>> wrote: >>> public class Country >>> { >>> ... >>> ... >>> public IEnumerable<Person> People{get; private set;} >>> } >>> >>> using(var session = sf.OpenSession()) >>> { >>> var china = s.QueryOver<Country>().Where(x=> x.Name == >>> "China").SingleOrDefault(); >>> foreach(var person in china.People) >>> { >>> DoSomethingButComeBackTomorrowToSeeResult(); >>> } >>> } >>> >>> The link that Roger gave you is correct what is incorrect is the design >>> of the domain. >>> >>> On Mon, Apr 4, 2011 at 2:33 PM, Dzyann Leleur <[email protected]<mailto: >>> [email protected]>> wrote: >>> Hi Fabio, >>> What do you mean with that trying to map a collection that big is wrong? >>> Do you mean like I shouldn't use NHibernate? Or that the collection >>> shouldn't be that big? >>> The collection is being created by a service, we don't have a choice but >>> having that collection, there is no other way. The service is not working >>> with Nhibernate to create the data. We are using Nhibernate for the User >>> interface part, that creates queries on the data. But has the option to >>> delete them too. >>> >>> When I saw how Nhibernate was behaving, I thought that maybe I shouldnt >>> try to delete the collection with Nhibernate and just do it with SQL, but I >>> wanted to see different options. >>> I am going to try the "on-delete="cascade"", but, was the approach I >>> implemented following the link: >>> >>> http://www.nhforge.org/doc/nh/en/index.html#performance-collections-oneshotdelete >>> that Roger gave me, wrong? >>> >>> Regards, >>> >>> Dzy.- >>> >>> On Sun, Apr 3, 2011 at 10:04 PM, Fabio Maulo <[email protected] >>> <mailto:[email protected]>> wrote: >>> try to map a collection with 95K items is simple wrong and nothing more. >>> btw you can use on-delete="cascade" >>> >>> >>> On Fri, Apr 1, 2011 at 6:23 PM, Dzyann <[email protected]<mailto: >>> [email protected]>> wrote: >>> Hi, >>> >>> I have a an entity Query that has a lot of items Metadata in a >>> relation "one-to-many". >>> When I delete the Query, I want all its childs to be delete too, so I >>> set cascade to all-delete-orphan. >>> >>> The items get deleted, but it takes a lot of time. The query can have >>> many items, lets say 95k items. >>> I checked out with the SQL Profiler to see what was going on, and I >>> saw that each Metadata Item is getting deleted one by one like: >>> >>> exec sp_executesql N'DELETE FROM MyDatabase.dbo.[QueryMetadata] WHERE >>> Id = @p0',N'@p0 int',@p0=302401 >>> >>> This takes time, and produces a bad user experience. I would like to >>> hear out any recommendations. >>> Maybe is better if I delete the items with a sql sentence? >>> >>> Thanks in advance for your help! >>> >>> Dzy.- >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "nhusers" group. >>> To post to this group, send email to [email protected]<mailto: >>> [email protected]>. >>> To unsubscribe from this group, send email to >>> [email protected]<mailto: >>> nhusers%[email protected]>. >>> For more options, visit this group at >>> http://groups.google.com/group/nhusers?hl=en. >>> >>> >>> >>> >>> -- >>> Fabio Maulo >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "nhusers" group. >>> To post to this group, send email to [email protected]<mailto: >>> [email protected]>. >>> To unsubscribe from this group, send email to >>> [email protected]<mailto: >>> nhusers%[email protected]>. >>> For more options, visit this group at >>> http://groups.google.com/group/nhusers?hl=en. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "nhusers" group. >>> To post to this group, send email to [email protected]<mailto: >>> [email protected]>. >>> To unsubscribe from this group, send email to >>> [email protected]<mailto: >>> nhusers%[email protected]>. >>> For more options, visit this group at >>> http://groups.google.com/group/nhusers?hl=en. >>> >>> >>> >>> -- >>> Fabio Maulo >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "nhusers" group. >>> To post to this group, send email to [email protected]<mailto: >>> [email protected]>. >>> To unsubscribe from this group, send email to >>> [email protected]<mailto: >>> nhusers%[email protected]>. >>> For more options, visit this group at >>> http://groups.google.com/group/nhusers?hl=en. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "nhusers" group. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]. >>> For more options, visit this group at >>> http://groups.google.com/group/nhusers?hl=en. >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "nhusers" group. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]. >>> For more options, visit this group at >>> http://groups.google.com/group/nhusers?hl=en. >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "nhusers" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/nhusers?hl=en. >> > > > > -- > Fabio Maulo > > -- > You received this message because you are subscribed to the Google Groups > "nhusers" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nhusers?hl=en. > -- You received this message because you are subscribed to the Google Groups "nhusers" group. 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