Which View helps in querying high I/O statements?

Which of the following generates the PLAN for SQL statements?

In which version of Oracle is AWR Introduced ?

Which user owns all the package of STATSPACK?

If commission is null then the text “Not Applicable” must be displayed, instead of blank space. How do I write the query?

Which data dictionary object is used to retrieve the information about the tables from a given schema?

A transaction is a set of SQL statements between any two COMMIT and ROLLBACK statements.

Data Dictionary in oracle is used to store information about various physical and logical Oracle structures e.g.Tables, Tablespaces, datafiles, etc

Can Check constraint be used for self referential integrity ?

What are the states of a rollback segment ?

Is the below query allowed?Select sal, ename Into x From emp Where ename = 'KING' (Where x is a record of Number(4) and Char(15));

A table has the following data : [[5, Null, 10]].What will the average function return ?

Consider a sequence whose currval is 1 and gets incremented by 1 by using the nextval reference we get the next number 2.Suppose at this point we issue an rollback and again issue a nextval.What will the output be ?

Which of these following features are correct if SQL is a set-oriented language?