Set - 6

Question 56 :

What are the usage of SAVEPOINTS ?value in a session before accessing next value ?

Answer :

SAVEPOINTS are used to subdivide a transaction into smaller parts. It enables rolling back part of a transaction. Maximum of five save points are allowed.

Question 57 :

What is ROWID ?in a session before accessing next value ?

Answer :

ROWID is a pseudo column attached to each row of a table. It is 18 character long, blockno, rownumber are the components of ROWID.

Question 58 :

Explain Connect by Prior ?in a session before accessing next value ?

Answer :

Retrieves rows in hierarchical order.e.g. select empno, ename from emp where.

Question 59 :

How many LONG columns are allowed in a table ? Is it possible to use LONG columns in WHERE clause or ORDER BY ?

Answer :

Only one LONG columns is allowed. It is not possible to use LONG column in WHERE or ORDER BY clause.

Question 60 :

What is Referential Integrity ?

Answer :

Maintaining data integrity through a set of rules that restrict the values of one or more columns of the tables based on the values of primary key or unique key of the referenced table.