User Guide > Push-Based Incremental Caching > View Requirements and Restrictions for Push-Based Incremental Caching
 
View Requirements and Restrictions for Push-Based Incremental Caching
When you decide to use a view for push-based incremental caching, you must consider how the view is defined and how the data source is monitored for change capture.
Subscribed views must have explicitly defined or implicitly inferred keys. Composite views (subqueries) are supported if they occur in the FROM clause. Incremental caches do not support INTERVALDAYTOSECOND and INTERVALYEARTOMONTH data types as key values.
The following view operators are supported.
Operator
Supported
Renaming
Yes.
Example: C1 AS C2
Projection
Yes, for creating a view from two table columns with scalar function support.
Example: SELECT UPPER(C1)
Selection
Yes, with scalar function support.
Example: WHERE LOWER(C1) = ‘abc’
Inner Join
Yes.
Left Outer Join
Yes, if only the left side is monitored by GoldenGate. Otherwise, no. The restriction applies because processing of the data change for left outer joins could result in inaccurate data.
Right Outer Join
Yes, if only the right operand is monitored by GoldenGate. Otherwise, no. The restriction applies because processing of the data change for right outer joins could result in inaccurate data.