This type of operation is related to the SQL statement containing the view. When an SQL statement is hard-parsed, if the views in the SQL statement are not merged, the following operations may appear in the execution plan of the related SQL statement according to different specific scenarios.
1）VIEW
Create an intermediate view of data, generally divided into system view and user view. When the optimizer generates an execution plan for a SQL statement, the subquery or view in the SQL statement cannot be merged with the main query (for example: the subquery or view needs to be grouped or rownum is obtained, etc.), this operation will occur Based on the execution plan of the SQL statement. This operation is specifically shown in node 1 in Figure 8-1.
Figure 8-1 Example of view-related operations VIEW
2）VIEW PUSHED PREDICATE