10+ Plsql Developer Interview Questions and Answers for Freshers

Code to pull-up mass data from one table and load into another table efficiently

• Use INSERT INTO SELECT statement to pull data from source table and load into target table

• Use WHERE clause to filter data if required

• Use INDEXES on columns used in WHERE clause to improve performance

• Use BULK COLLECT to fetch data in batches to improve performance

• Use PARALLEL hint to execute the query in parallel if the table is large

• Use NOLOGGING option to improve performance by reducing redo log ...read more

Explanation of SQL Loader, Procedure, Package, Function, Bulk Collect, Cursor

• SQL Loader is a tool used to load data from external files into Oracle database tables

• Procedure is a named block of PL/SQL code that performs a specific task

• Package is a collection of related procedures, functions, variables, and cursors

• Function is a named block of PL/SQL code that returns a value

• Bulk Collect is a method used to fetch multiple rows of data from a query into a collection

• Cursor is a po...read more

I wrote a procedure to calculate the average salary of employees in a department.

• Used cursor to fetch employee data

• Calculated total salary using loop

• Divided total salary by number of employees

• Handled exceptions for zero employees in department

I work on performance optimization by analyzing query execution plans, indexing, and code refactoring.

• Analyzing query execution plans to identify bottlenecks

• Creating appropriate indexes to improve query performance

• Refactoring code to optimize resource usage

• Using tools like Explain Plan and SQL Tuning Advisor

Join is used to combine rows from two or more tables based on a related column between them.

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• INNER JOIN returns rows when there is at least one match in both tables

• LEFT JOIN returns all rows from the left table and the matched rows from the right table

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table

• FULL JOIN returns rows when there is a match in one of the tables

Char is fixed length while Varchar2 is variable length.

• Char takes up the same amount of space regardless of the data it contains.

• Varchar2 only takes up as much space as the data it contains.

• Char is useful for storing data that is always the same length, like a phone number.

• Varchar2 is useful for storing data that can vary in length, like a name or address.

Developed a PL/SQL project for managing inventory and sales data in a retail store.

• Designed database tables to store product information, sales transactions, and customer details.

• Implemented PL/SQL procedures and functions for adding, updating, and querying data.

• Created triggers to enforce business rules and maintain data integrity.

• Developed reports using PL/SQL queries to analyze sales performance and inventory levels.

A PL/SQL function is a named PL/SQL block that returns a value.

• Functions are used to perform a specific task and return a single value.

• They can accept input parameters and return a value.

• Functions can be called from SQL statements or other PL/SQL blocks.

Write a program to calculate the factorial of a given number.

• Create a function to calculate the factorial recursively or iteratively.

• Handle edge cases like negative numbers or zero.

• Use a loop to multiply numbers from 1 to the given number to calculate the factorial.

Bulk collect is a feature in PL/SQL that allows for fetching multiple rows of data at once.

• Improves performance by reducing context switches between the PL/SQL engine and SQL engine

• Reduces network traffic by fetching multiple rows in a single round trip

• Can be used with SELECT INTO or FETCH INTO statements