DML trigger plan guide

There are two options for designing DML triggers:

• Execute the instead trigger instead of the usual trigger operation. You can also define the instead
  Triggers. These triggers can extend the update types supported by the view.

• Execute the after Trigger After executing the insert, update, or delete statement operation. The specified after is the same as the specified. After
  Triggers can only be specified on tables.

The following table compares the functions of the After trigger and the instead of trigger.

Function	After trigger	Instead of trigger
Applicability	Table	Tables and views
Number of triggers contained in each table or view	Each trigger operation (Update, delete, and insert) contains multiple triggers.	Each trigger operation (Update, delete, and insert) contains a trigger.
Cascade references	No restrictions	The instead of update and delete triggers cannot be used on tables that serve as the target of cascading integrity constraints.
Run	Later: Constraint Processing Declarative reference operation CreateInsertedAndDeletedTable Trigger operation	Earlier: Constraint Processing Alternative: Trigger operation Later: CreateInsertedAndDeletedTable
Execution sequence	You can specify the first and last executions.	Not applicable
InsertedAndDeletedTableVarchar (max),Nvarchar (max)And Varbinary (max)Column reference.	Allow	Allow
InsertedAndDeletedTableText,NtextAndImage Column reference.	Not Allowed	Allow