SMC Corporation Plsql Developer Interview Questions and Answers

A cursor is a pointer to a private SQL area that stores information about the processing of a SELECT or DML statement.

• A cursor is used to retrieve data row by row from a result set.

• There are two types of cursors: Implicit and Explicit.

• Implicit cursors are used for single-row queries, while explicit cursors are used for multi-row queries.

• Cursor variables can be used to pass cursors as parameters to procedures and functi...read more

Truncate removes all data from a table while delete removes specific rows.

• Truncate is faster than delete as it doesn't log individual row deletions

• Truncate cannot be rolled back while delete can be

• Truncate resets the identity of the table while delete doesn't

• Truncate doesn't fire triggers while delete does

A trigger is a special type of stored procedure that automatically executes in response to certain events.

• Triggers are used to enforce business rules or to perform complex calculations.

• They can be defined to execute before or after a data modification operation.

• Triggers can be used to audit changes to data or to replicate data changes to other tables.

• Examples of events that can trigger a trigger include INSERT, UPDATE,...read more