Okay, I see what on-delete cascade does at the database level. This assumes you put on cascading delete foreign keys on the database level as well. Guess I'll have to atleast make that change in order for this to work (which I can do and is fairly minor).
On Aug 27, 9:32 am, MattO <[email protected]> wrote: > Also, I found the documentation on the on-delete option that appears > to be missing from the nHibernate documentation > here:http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html > > It is only valid on <key> nodes though, not sure if you can add on- > delete to key-property tags on a composite key. I'm guessing not, so > I may have to make some database changes and code changes. > > On Aug 27, 2:54 am, nadav s <[email protected]> wrote: > > > > > the simplest solution is instead of setting cascade delete, in the > > DAO/Repository, when deleting the father entity, use an HQL delete statement > > on the children where their FatherId = the deleted father. > > > On Fri, Aug 27, 2010 at 9:45 AM, Frans Bouma <[email protected]> wrote: > > > > there are 2 things I see that would cause this situation. > > > > 1. you are using the native generator. this usually means the database > > > > controls the PK instead of the application. the downside to this > > > > approach > > > is > > > > you loose the ability to batch CUD statements. I would strongly > > > > recommend > > > > switching to either guid.comb or hilo. > > > > > 2. if you have the cascade attribute set for the key of your collections > > > > it's set to noaction, which means the database will do nothing. change > > > this > > > > to on-delete="cascade" and the database will delete them automatically > > > > (assuming the db has this feature). if the on-delete attribute does not > > > > exist, add it with the option to cascade. > > > > this should fix the problem. > > > > and assuming the entities aren't connected through multiple paths > > > :) > > > > > if the database does not support cascades, then NH must manage the > > > deletes, > > > > in which case option 1 above becomes very important. without batching > > > > the > > > > entities will be removed one at a time. > > > > Doesn't NH support some kind of direct delete feature? I.e. delete > > > entities in bulk matching a given set of predicates? Which then results in > > > queries like DELETE FROM Foo WHERE ... > > > > IMHO that should make MattO's problem go away instantly. > > > > FB > > > > > On Aug 26, 6:50 pm, MattO <[email protected]> wrote: > > > > > Okay, here they are (shortened). Basically there is one ContentCode > > > > > (parent) to usually 300 to 400 ContentCodeDetails. > > > > > > Then for every user in the system that has access to the content code > > > > > details there could be up to 2000 to 4000 records for EACH user in the > > > > > ContentCodeAccess table. > > > > > > The problem is if I delete a parent, it deletes it with one delete > > > > > statement, then it deletes the 300 to 400 ContentCodeDetails with 300 > > > > > to 400 DELETE statements, and finally it deletes the ContentCodeAccess > > > > > records with 2000 to 4000 delete statements. > > > > > > In my old ADO .NET code I did this in less than a second by running 3 > > > > > delete statements. Now it executes around 2500 to 4000 delete > > > > > statements when I delete a parent record and takes 40 to 60 seconds. > > > > > > Here is the Parent (ContentCode): > > > > > > <class name="ItemBankCoreNH.BusinessObjects.ContentCode, > > > > > ItemBankCoreNH" table="[dbo].[ContentCodes]" > > > > > optimistic-lock="version" dynamic-update="true" > > > > > lazy="true"> > > > > > <id name="Id" column="[ContentCodeID]"> > > > > > <generator class="native" /> > > > > > </id> > > > > > <version name="TS" generated="always" unsaved-value="null" > > > > > type="BinaryBlob"> > > > > > <!-- Generated="always" is to have database handle > > > > > generation of timestamp --> > > > > > <column name="TS" not-null="false" sql-type="timestamp"/> > > > > > </version> > > > > > ... More properties.... > > > > > <bag name="ExamTypes" lazy="true" cascade="none"> > > > > > <key column="[Type]" property-ref="ExamType" not- > > > > > null="true" on-delete="noaction" update="false"></key> > > > > > <one-to-many class="ExamType" /> > > > > > </bag> > > > > > <bag name="ContentCodeDetails" inverse="true" cascade="all- > > > > > delete-orphan" lazy="true"> > > > > > <key not-null="true"> > > > > > <column name="[ContentCodeID]" sql-type="int" /> > > > > > </key> > > > > > <one-to-many class="ContentCodeDetail" /> > > > > > </bag> > > > > > </class> > > > > > > Here is the Child (ContentCodeDetails): > > > > > > <class name="ItemBankCoreNH.BusinessObjects.ContentCodeDetail, > > > > > ItemBankCoreNH" table="[dbo].[ContentCodeDetail]" > > > > > optimistic-lock="version" dynamic-update="true" > > > > > lazy="true"> > > > > > <id name="Id" column="[ContentID]"> > > > > > <generator class="native" /> > > > > > </id> > > > > > <version name="TS" generated="always" unsaved-value="null" > > > > > type="BinaryBlob"> > > > > > <!-- Generated="always" is to have database handle > > > > > generation of timestamp --> > > > > > <column name="TS" not-null="false" sql-type="timestamp"/> > > > > > </version> > > > > > <property name="ContentCodeID" column="[ContentCodeID]" /> > > > > > .... More Properties... > > > > > <many-to-one name="ContentCodeParent" class="ContentCode" > > > > > insert="false" update="false" fetch="join"> > > > > > <column name="[ContentCodeID]" sql-type="int" /> > > > > > </many-to-one> > > > > > <bag name="ContentCodeAccessDetails" cascade="all-delete- > > > > > orphan" lazy="true"> > > > > > <key not-null="true"> > > > > > <column name="[ContentID]" sql-type="int" /> > > > > > </key> > > > > > <one-to-many class="ContentCodeAccess" /> > > > > > </bag> > > > > > </class> > > > > > > And finally the table with the most records (ContentCodeAccess): > > > > > > <class name="ItemBankCoreNH.BusinessObjects.ContentCodeAccess, > > > > > ItemBankCoreNH" table="[dbo].[ContentCodeAccess]" > > > > > optimistic-lock="version" dynamic-update="true" > > > > > lazy="true"> > > > > > <composite-id> > > > > > <key-property name="ContentID" column="[ContentID]" /> > > > > > <key-property name="DomainUser" column="[DomainUser]" /> > > > > > <key-property name="ExamType" column="[ExamType]" /> > > > > > <key-property name="ContentCodeTypeID" > > > > > column="[ContentCodeTypeID]" /> > > > > > </composite-id> > > > > > <version name="TS" generated="always" unsaved-value="null" > > > > > type="BinaryBlob"> > > > > > <!-- Generated="always" is to have database handle > > > > > generation of timestamp --> > > > > > <column name="TS" not-null="false" sql-type="timestamp"/> > > > > > </version> > > > > > </class> > > > > > > On Aug 26, 3:57 pm, Jason Meckley <[email protected]> wrote: > > > > > > > inverse means the root entity is not responsible for the id of > > > > > > child. > > > > > > the child is itself an entity and will manage it's own POID. > > > > > > > What do you're mappings look like? I would assume you have > > > > > > cascade="all" or all-delete-orphan. The strategies will use NH to > > > > > > manage the deletion rather than letting the database delete child > > > > > > relations through FK cascades. > > > > > > > if you set cascade="save-update" with the key as on-delete="cascade" > > > > > > the database should manage the deletion of related entities, if it > > > > > > supports cascade deletes. if it doesn't you can also look into > > > > > > batching ADO.Net calls. This may not work depending on your POID > > > > > > strategy. > > > > > > > On Aug 26, 4:22 pm, MattO <[email protected]> wrote: > > > > > > > > How do you overcome the issue with nHibernate where collections > > > > > > > that are mapped with inverse="true" will be issued a delete > > > > > > > statement for every object in the collection? > > > > > > > > Right now this has added about 50 seconds to a single delete > > > > > > > operation which normally only took less than a second to perform > > > > > > > in straight ADO .NET by performing a delete based on the primary > > > > > > > key of the parent. > > > > > > > > According to the nHibernate reference manual section 17.5.4 (one > > > > > > > shot delete), by discarding (dereferencing) the original > > > > > > > collection and returning a newly instantiated collection with all > > > > > > > the current elements. > > > > > > > > Can someone please tell me what they mean with a code sample if > > > > > > > this also applys to inverse="true" collections, or is there some > > > > > > > other option other then manually handling deletes for these types > > > > > > > of collections yourself?- Hide quoted text - > > > > > > > - Show quoted text - > > > > > -- > > > > 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]<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]<nhusers%[email protected]> > > > . > > > For more options, visit this group at > > ... > > read more »- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "nhusers" group. 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