Top 50 Oracle Interview Questions and Answers

Oracle database architecture is a set of components that work together to manage data storage and retrieval.

• Oracle database architecture consists of physical and logical structures

• Physical structures include data files, redo logs, and control files

• Logical structures include tablespaces, schema objects, and segments

• Oracle database architecture also includes background processes and memory structures

• Oracle database architecture supports client-server architecture and distribute...read more

Yes, I have knowledge of both Oracle and SAP.

• I have experience working with Oracle databases and SAP ERP systems.

• I am familiar with Oracle's SQL and PL/SQL languages.

• I have used SAP modules such as SAP FI/CO and SAP MM.

• I have completed training courses on Oracle and SAP.

• I have successfully implemented Oracle and SAP solutions in previous projects.

Oracle has drawbacks such as high cost, complexity, and limited scalability.

• High cost: Oracle database licenses and support can be expensive.

• Complexity: Oracle has a steep learning curve and can be complex to manage and administer.

• Limited scalability: Oracle may not scale well for large and rapidly growing datasets.

• Vendor lock-in: Once a company invests in Oracle, it can be difficult to switch to another database system.

• Lack of flexibility: Oracle's rigid structure and archit...read more

Oracle DB is a proprietary RDBMS while SQL DB is a generic term for any RDBMS that uses SQL as its language.

• Oracle DB is developed and marketed by Oracle Corporation while SQL DB is a generic term for any RDBMS that uses SQL as its language.

• Oracle DB is a proprietary RDBMS while SQL DB is a generic term for any RDBMS that uses SQL as its language.

• Oracle DB has its own PL/SQL language while SQL DB uses SQL as its language.

• Oracle DB is more expensive than SQL DB.

• Oracle DB is mo...read more

Oracle DR setup involves configuring standby database, data replication, and failover testing.

• Identify primary and standby database servers

• Configure data replication using Oracle Data Guard

• Perform failover testing to ensure data consistency

• Monitor and maintain DR setup regularly

In the Initialization phase of SUM shadow instance is created.

• Shadow instance is created during the Initialization phase of SUM.

• It is used for testing and validation before making changes to the actual system.

• Helps in minimizing risks and ensuring smooth transition during updates.

• Example: In SAP system update management (SUM), shadow instance is created in the Initialization phase.

ERP integration with Oracle can streamline store operations and improve efficiency.

• Integrate ERP system with Oracle for real-time data exchange

• Automate inventory management and procurement processes

• Utilize Oracle's analytics and reporting capabilities for better decision-making

• Implement security measures to protect sensitive data

• Train employees on new system to ensure successful adoption

Forms personalization allows users to customize their own forms without modifying the underlying code, while customization involves making changes to the form's code.

• Forms personalization is done by end users without technical knowledge.

• Customization involves modifying the form's code by developers.

• Forms personalization is limited to changing the behavior of existing form elements.

• Customization allows for more extensive changes to the form's functionality.

• Forms personalizatio...read more

Collection in Oracle is a group of elements of the same data type. Types include VARRAY, Nested Table, and Associative Array.

• VARRAY is a fixed-size array that can hold a varying number of elements up to the specified limit.

• Nested Table is a dynamic array with no fixed size that can be stored in a database column.

• Associative Array is a collection of key-value pairs where the key is unique and used to access the corresponding value.

ORA-00600 is an internal error code that indicates a software bug or corrupted data.

• ORA-00600 is a generic error message that indicates an internal error has occurred.

• It is caused by a software bug or corrupted data.

• It is a critical error that requires immediate attention from the DBA.

• The error message includes a code that identifies the specific error.

• The error can be resolved by applying a patch or contacting Oracle support.

• Examples of ORA-00600 errors include: ORA-00600: i...read more

DBMS in Oracle stands for Database Management System, which is a software that manages the storage, retrieval, and organization of data in a database.

• DBMS in Oracle is a software system that allows users to define, create, maintain, and control access to the database.

• It provides an interface for users to interact with the database and perform various operations like querying, updating, and managing data.

• Oracle Database is a popular DBMS that offers features such as data secur...read more

In Oracle, a server refers to a computer system that hosts the Oracle database software and manages data storage, access, and processing.

• A server in Oracle is a computer system dedicated to running the Oracle database software.

• It manages data storage, access, and processing for the Oracle database.

• Examples of Oracle servers include Oracle Exadata, Oracle Database Appliance, and Oracle Cloud Infrastructure.

Oracle in software refers to Oracle Corporation, a multinational computer technology corporation known for its database management systems.

• Oracle is a leading provider of relational database management systems (RDBMS).

• It offers a wide range of products and services for data management, cloud applications, and more.

• Oracle databases are widely used in enterprise applications for storing and managing data efficiently.

• Examples of Oracle products include Oracle Database, Oracle Fu...read more

Collections in Oracle are data structures that store and manipulate groups of data.

• Collections can be used to store data in arrays, lists, or sets.

• They can be used to pass data between PL/SQL blocks or between PL/SQL and SQL.

• Examples of collections include VARRAYs, nested tables, and associative arrays.

Oracle PL/SQL is a procedural language extension for SQL used to write stored procedures, functions, and triggers.

• PL/SQL stands for Procedural Language/Structured Query Language

• It is used to enhance the capabilities of SQL by adding procedural constructs

• PL/SQL code is executed on the Oracle Database server

• It allows the creation of stored procedures, functions, packages, and triggers

• PL/SQL can be used for data manipulation, data definition, and data control

• Example: CREATE PROC...read more

Dual is a special one-row, one-column table in Oracle DB.

• Dual is used to perform calculations or execute functions without selecting from a table.

• It is often used to generate a sequence of numbers or to concatenate strings.

• For example, SELECT 1+1 FROM dual; will return 2.

• Dual is automatically created by Oracle and is always available in every Oracle database.

As a Product Manager at Oracle, I led data analytics initiatives to improve product performance and customer experience.

• Developed and implemented data-driven strategies to optimize product features and pricing.

• Analyzed customer behavior and feedback to identify areas for improvement.

• Collaborated with cross-functional teams to design and launch new products based on market trends and customer needs.

• Used data visualization tools to present insights and recommendations to senior...read more

Yes, I have worked on Oracle Dataguard.

• I have experience in configuring and managing Oracle Dataguard for disaster recovery.

• I have performed switchover and failover operations to test the failover mechanism.

• I have monitored and resolved issues related to Dataguard synchronization and network connectivity.

• I have also worked on configuring Active Dataguard for read-only reporting purposes.

Data can be moved from Oracle source to data Lake on Azure using Azure Data Factory.

• Use Azure Data Factory to create a pipeline for moving data from Oracle source to Azure Data Lake

• Set up linked services in Azure Data Factory for Oracle and Azure Data Lake

• Use copy activity in Azure Data Factory to move data from Oracle to Azure Data Lake

• Monitor and manage the data movement process in Azure Data Factory

SLA in Oracle PA is a set of rules that define the level of service provided to customers.

• SLA is defined at the service level and can be customized for each customer

• It includes metrics such as response time, resolution time, and availability

• SLA violations can trigger alerts and escalations

• SLA reports can be generated to track performance

• Example: A customer may have an SLA that requires a response within 2 hours and a resolution within 24 hours

Oracle fetches data using the SQL engine and the buffer cache.

• When a select statement is executed, the SQL engine parses the statement and creates an execution plan.

• The execution plan is used to fetch data from the database.

• The buffer cache is used to store frequently accessed data in memory for faster access.

• Oracle uses a multiversion read consistency model to ensure that data is consistent.

• Data is fetched in blocks called database blocks, which are stored on disk.

• Oracle use...read more

An insert/update statement in Oracle database is parsed by the SQL parser to check syntax and semantics.

• The SQL parser first checks the syntax of the insert/update statement to ensure it follows the rules of the SQL language.

• Next, the parser checks the semantics of the statement, which involves verifying the existence and accessibility of the tables and columns referenced in the statement.

• During parsing, the parser also determines the execution plan for the statement, which i...read more

Oracle and SAP are both enterprise resource planning (ERP) software, but Oracle is known for its database management system while SAP is known for its business process management.

• Oracle is known for its database management system, while SAP is known for its business process management.

• Oracle offers a wide range of products and services, including databases, cloud solutions, and enterprise software, while SAP focuses primarily on business applications.

• Oracle's primary database...read more

Oracle type accounts can be configured in CPM by setting up the necessary permissions and access controls.

• Create a new user account in Oracle with the appropriate permissions for CPM access

• Assign the user account to the CPM application role

• Configure the user account settings in CPM to define access levels and restrictions

Partitions in Oracle are a way to divide a large table into smaller, more manageable pieces.

• Partitions allow for faster querying and maintenance of large tables

• They can be based on a range of values, a list of values, or a hash function

• Partitioning can be done on tables, indexes, and materialized views

• Examples of partitioning include partitioning by date, region, or customer ID

Yes, OIC can be triggered using ess job.

• OIC can be triggered using Oracle Integration Cloud (OIC) REST APIs.

• ESS job can be used to schedule and trigger OIC integrations.

• By configuring the ESS job to call the OIC REST API endpoint, OIC can be triggered.

• This allows for automation and scheduling of OIC integrations.

Oracle and Cerner are popular choices for healthcare organizations due to their robust features, scalability, and industry-specific functionalities.

• Oracle offers a comprehensive suite of healthcare solutions, including electronic health records (EHR) and population health management.

• Cerner is known for its interoperability capabilities, allowing seamless data exchange between different healthcare systems.

• Both Oracle and Cerner have a strong presence in the healthcare industry...read more

Explain plan is a tool in Oracle that shows the execution plan of a SQL statement.

• Explain plan is used to analyze and optimize SQL queries.

• It shows the order in which tables are accessed, the join methods used, and the access methods used.

• The output of explain plan can be viewed in text or graphical format.

• It helps in identifying performance bottlenecks and optimizing the query execution time.

• Explain plan can be generated using the EXPLAIN PLAN statement or the DBMS_XPLAN pac...read more

Oracle database structure refers to the organization of data in tables, indexes, views, and other database objects.

• Consists of tables, which store data in rows and columns

• Includes indexes for faster data retrieval

• Views provide virtual representations of data from one or more tables

• Constraints ensure data integrity and enforce rules

• Stored procedures and functions for processing data

The process of cloning a database differs between cdb and noncdb databases.

• In cdb databases, the clone process involves creating a new PDB by copying the existing PDB's metadata and data files.

• In noncdb databases, the clone process involves creating a new database by copying the existing database's data files and redo logs.

• CDB clones can be created using the DBMS_PDB package, while non-CDB clones can be created using RMAN or the DUPLICATE command.

• CDB clones can be created as ...read more

What-if analysis in Oracle Policy Automation is a tool that allows users to simulate different scenarios and evaluate their impact on policy outcomes.

• Users can create hypothetical scenarios by changing input values and assumptions

• The tool then calculates the impact of these changes on policy outcomes

• This helps users make informed decisions and identify potential risks and opportunities

• For example, a user can simulate the impact of changing eligibility criteria on the number o...read more

Pragma autonomous transactions allow a PL/SQL subprogram to commit or rollback its own transactions independently of its caller.

• Pragma autonomous transactions are used to execute a transaction independently of the main transaction.

• It allows a subprogram to commit or rollback its own transactions without affecting the main transaction.

• Autonomous transactions are often used for logging, auditing, or error handling purposes.

• To declare an autonomous transaction, use the PRAGMA AU...read more

Oracle Block Change is a feature that tracks and records changes made to database blocks.

• Oracle Block Change is used for efficient data replication and synchronization.

• It helps in identifying and transferring only the changed data blocks instead of the entire database.

• Oracle GoldenGate utilizes Oracle Block Change technology for real-time data integration.

• Block Change Tracking (BCT) is a feature in Oracle Database that enables incremental backups by tracking changed blocks.

A function in Oracle Database is a named PL/SQL block that can accept parameters and return a value.

• Functions can be used to perform calculations, manipulate data, or return specific values.

• They can be called from SQL queries or other PL/SQL blocks.

• Functions must return a single value of a specified data type.

The flow of process in Oracle involves defining requirements, designing solutions, implementing, testing, and deploying.

• Define requirements based on business needs

• Design solutions using Oracle tools and technologies

• Implement the designed solutions

• Test the implemented solutions for functionality and performance

• Deploy the tested solutions for production use

Transitioning from Oracle to Data Engineering

• Learn SQL and database concepts

• Familiarize with ETL tools like Apache NiFi and Talend

• Gain knowledge of big data technologies like Hadoop and Spark

• Develop skills in programming languages like Python and Java

• Understand data modeling and schema design

• Get hands-on experience with cloud platforms like AWS and Azure

Oracle upgrade involves planning, testing, and executing the upgrade process.

• Identify the current and target versions

• Review the upgrade documentation and release notes

• Perform a test upgrade in a non-production environment

• Backup the database before upgrading

• Run the pre-upgrade script to identify potential issues

• Upgrade the software and database components

• Run the post-upgrade script to complete the upgrade process

• Perform functional and performance testing after the upgrade

Oracle supports various data types including numeric, character, date, and LOB types.

• Numeric data types include NUMBER, INTEGER, and FLOAT.

• Character data types include CHAR, VARCHAR2, and CLOB.

• Date data types include DATE and TIMESTAMP.

• LOB data types include BLOB and CLOB.

Subqueries in Oracle are queries nested within another query to retrieve data from multiple tables.

• Subqueries can be used in SELECT, INSERT, UPDATE, and DELETE statements.

• Subqueries can return a single value, a single row, multiple rows, or a table.

• Subqueries can be correlated or non-correlated, depending on whether they reference columns from the outer query.

• Example: SELECT * FROM employees WHERE department_id = (SELECT department_id FROM departments WHERE department_name = ...read more

Oracle partitioning is a technique to divide large tables into smaller, more manageable pieces.

• Partitioning improves query performance by reducing the amount of data that needs to be scanned.

• Partitioning can be done based on range, list, hash, or composite methods.

• Partitioning can also be done vertically, where columns are divided into separate partitions.

• Partitioning requires careful planning and consideration of the data and queries involved.

• Examples of partitioning include...read more

Oracle and WMS software are both commonly used in the field of supply chain management.

• Oracle is a database management system often used for storing and managing supply chain data.

• WMS (Warehouse Management System) software is used to manage inventory and operations within a warehouse.

• Oracle can be integrated with WMS software to provide a comprehensive supply chain management solution.

• Examples of WMS software that can be integrated with Oracle include SAP, Manhattan Associate...read more

Oracle bill in advance accounting entries

• When billing in advance, recognize revenue over the service period

• Debit Accounts Receivable and credit Unearned Revenue upon billing

• Recognize revenue by debiting Unearned Revenue and crediting Revenue over time

• Adjust entries as revenue is earned

Oracle EBS is an integrated suite of business applications for managing various aspects of a business.

• Oracle EBS stands for Oracle E-Business Suite

• It includes modules for financials, supply chain management, human resources, and more

• Oracle EBS helps organizations streamline their business processes and improve efficiency

Components of logical database structure in Oracle include tables, views, indexes, sequences, and synonyms.

• Tables: Store data in rows and columns.

• Views: Virtual tables based on SQL query results.

• Indexes: Improve query performance by providing quick access to rows.

• Sequences: Generate unique numbers for primary key values.

• Synonyms: Alias for database objects to simplify queries.

Oracle database architecture consists of memory structures, background processes, and physical files.

• Oracle database has a shared memory architecture

• Memory structures include SGA and PGA

• Background processes include PMON, SMON, DBWR, LGWR, etc.

• Physical files include data files, control files, redo log files, etc.

• expdp is a utility used for exporting data from an Oracle database

Oracle database architecture and multi-tenant architecture in Oracle 12c

• Oracle database architecture includes physical and logical structures

• Multi-tenant architecture in Oracle 12c allows multiple pluggable databases to share a single container database

• Each pluggable database has its own set of tablespaces, users, and schemas

• This architecture reduces hardware and software costs and simplifies database management

Oracle database architecture consists of memory structures, background processes, and physical files.

• Memory structures include SGA and PGA

• Background processes include PMON, SMON, DBWn, LGWR, CKPT, etc.

• Physical files include data files, control files, redo log files, etc.

• Oracle database architecture follows a client-server model

• Oracle database architecture supports multi-tier architecture

There is no preference of working on Oracle over SAP based on my background.

• Both Oracle and SAP have their own strengths and weaknesses.

• The choice between Oracle and SAP depends on the specific requirements of the project or organization.

• Oracle is known for its robust database management system and comprehensive suite of business applications.

• SAP, on the other hand, is renowned for its integrated enterprise resource planning (ERP) solutions.

• It is important to evaluate factors...read more

SQL is a programming language used to manage and manipulate relational databases. Oracle is a relational database management system.

• SQL stands for Structured Query Language

• It is used to manage and manipulate data in relational databases

• Oracle is a popular relational database management system

• It is used to store and manage large amounts of data

• Oracle uses SQL as its primary programming language

To add a RAC node in 19c DB, you need to run the 'addNode.sh' script on the new node.

• Ensure the new node meets all the prerequisites for adding to the RAC cluster.

• Run the 'addNode.sh' script on the new node to add it to the existing RAC cluster.

• Verify the addition of the new node by checking the cluster status and resources.

Oacore issue refers to problems encountered in the Oracle Application Framework (OAF) layer of Oracle E-Business Suite.

• Oacore issues can cause application performance problems, such as slow page load times or unresponsive pages.

• Common causes of Oacore issues include memory leaks, database connectivity problems, and configuration errors.

• To troubleshoot Oacore issues, DBAs can use tools like Oracle Enterprise Manager (OEM) and log files to identify the root cause of the problem...read more

Oracle collections are data structures used to store and manipulate sets of data in PL/SQL.

• Collections can be nested within each other

• Types of collections include associative arrays, nested tables, and VARRAYs

• Collections can be used to pass multiple values to a function or procedure

• Collections can be used to bulk collect data from a query

• Collections can be declared as types or as variables

Use Oracle RMAN to clone database without downtime

• Use RMAN duplicate command to create a clone of the database

• Perform the clone on a separate server to avoid downtime

• Use incremental backups to reduce the time required for the clone

• Configure the clone to use a different database name and unique file locations

Partitioning in Oracle allows tables, indexes, and index-organized tables to be subdivided into smaller, more manageable pieces.

• Partitioning improves query performance by allowing operations to be performed on individual partitions instead of the entire table.

• Types of partitioning include range, list, hash, and composite partitioning.

• Example: Creating a range partitioned table based on a date column to store data for each month separately.

Oracle architecture is a multi-layered design that includes physical, memory, and process components.

• Oracle architecture consists of physical, memory, and process components.

• The physical component includes data files, control files, and redo log files.

• The memory component includes the System Global Area (SGA) and Program Global Area (PGA).

• The process component includes background processes and user processes.

• Oracle architecture is designed to provide high availability, scalab...read more

SQL is a language used to manage relational databases, while Oracle is a relational database management system.

• SQL is a language used to create, modify, and query databases.

• Oracle is a specific relational database management system that uses SQL.

• SQL can be used with other database management systems besides Oracle.

• Oracle has additional features beyond standard SQL, such as PL/SQL for procedural programming.

• SQL is a standard language, while Oracle is a specific product.

• SQL is ...read more

Collections in Oracle are data structures used to store and manipulate groups of data.

• Collections can be nested tables, varrays, or associative arrays.

• Nested tables are like one-dimensional arrays, varrays are like arrays with a maximum size, and associative arrays are like dictionaries.

• Collections can be used to pass multiple values as a single parameter to a stored procedure or function.

• Example: DECLARE TYPE emp_list IS TABLE OF employees%ROWTYPE;

• Example: DECLARE TYPE phone...read more

Oracle architecture refers to the structure and components of the Oracle database system.

• Oracle architecture consists of physical and logical components.

• Physical components include memory, storage, and processes.

• Logical components include instances, databases, and schemas.

• Oracle uses a client-server architecture.

• Oracle database is divided into tablespaces and data files.

• Oracle architecture supports high availability and scalability.

• Examples of Oracle architecture components a...read more

Examples of Oracle queries

• Use SELECT statement to retrieve data from a table

• Use WHERE clause to filter results based on a condition

• Use JOIN to combine rows from two or more tables based on a related column

Oracle database architecture consists of multiple components like instance, memory structures, and physical storage.

• Oracle database architecture includes instance, memory structures, and physical storage.

• Instance consists of background processes and memory structures like SGA and PGA.

• Physical storage includes data files, control files, and redo log files.

• Oracle database architecture allows for scalability, high availability, and performance tuning.

Oracle Architecture is the structure and components of the Oracle database system.

• Consists of physical and logical structures

• Physical structures include data files, control files, redo log files

• Logical structures include tablespaces, schema objects

• Uses memory structures like SGA and PGA for processing data

• Processes like background processes and server processes handle database operations

The architecture of Oracle database consists of multiple components like instance, memory structures, and physical and logical storage.

• Oracle database architecture includes an instance, which consists of memory structures like SGA and PGA.

• The instance is responsible for managing the database and executing user requests.

• Physical storage in Oracle database is organized into data files, control files, and redo log files.

• Logical storage includes tablespaces, which are divided int...read more

Oracle database architecture is a multi-tiered system with components like client, server, and storage.

• Consists of physical and logical structures

• Includes processes like SQL processing, memory management, and I/O management

• Client communicates with server through SQL*Net

• Server manages data storage and retrieval

• Storage includes data files, control files, and redo log files