After a result of the partial override is received, the system calculates changes for a DCR by comparing the obtained result with the entity in the database. Changes are generated according to the following algorithm:

• Attribute with the specified URI doesn’t exist in the result of partial override, but exists in the entity in the database - The DELETE_ATTRIBUTE change is generated.
• Attribute with the specified URI exists in the result of partial override, but doesn’t exist in the entity in the database - The INSERT_ATTRIBUTE change is generated.
• Attribute with the specified URI exists in the result of partial override and in the entity in the database (in case of partial override with preserveURIs option):
  • If the value was modified, the UPDATE_ATTRIBUTE change is generated.
  • If only pin/ignore flag for the attribute was modified, the PIN_ATTRIBUTE/IGNORE_ATTRIBUTE change is generated.
  • If both the value and the flag were modified, the UPDATE_ATTRIBUTE change is generated.
• Attribute with the specified URI exists in the result of partial override and in the entity in the database, and the values are the same - Change is not generated.

Table 1. Changes Generated After Partial Override

Attribute URI in the Partial Override Result	Attribute URI in the Database	Value of the Attribute in the Database vs the Result of Partial Override	Pin/Ignore Flag in the Database vs the Result of Partial Override	Extra Option	Generated Change
-	+	Only in the database	Only in the database	-/ preserveURIs	DELETE_ATTRIBUTE
+	-	Only in the request	Only in the request	-/ preserveURIs	INSERT_ATTRIBUTE
+	+	The same	Different	-	UPDATE_ATTRIBUTE
				preserveURIs	PIN_ATTRIBUTE/IGNORE_ATTRIBUTE
+	+	Different	The same	preserveURIs	UPDATE_ATTRIBUTE
+	+	Different	Different	preserveURIs	UPDATE_ATTRIBUTE
+	+	The same	The same	-/ preserveURIs	no changes are generated