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 -
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