Oracle SQL Database Administrator Interview Questions, Process, and Tips

SQL is a structured query language used for relational databases, while NoSQL is a non-relational database management system.

• SQL is used for structured data with predefined schema, while NoSQL is used for unstructured or semi-structured data.

• SQL databases are vertically scalable, while NoSQL databases are horizontally scalable.

• SQL databases are ACID compliant, ensuring data integrity, while NoSQL databases sacrifice so...read more

Restoring a database using RMAN involves connecting to the target database, restoring the control file, and recovering the database.

• Connect to the target database using RMAN

• Restore the control file from a backup

• Restore the datafiles and tablespaces

• Recover the database to bring it to a consistent state

• Perform necessary checks and validations after restoration

You can change a column in a table using the ALTER TABLE statement in SQL.

• Use the ALTER TABLE statement followed by the MODIFY keyword to change the data type or size of a column.

• Use the ALTER TABLE statement followed by the ADD or DROP keyword to add or remove a column.

• Make sure to specify the table name, column name, and the new data type or size when making changes.

Different types of objects in a database include tables, views, indexes, sequences, and stored procedures.

• Tables: Used to store data in rows and columns.

• Views: Virtual tables created by a query.

• Indexes: Improve the performance of queries by allowing quick access to specific rows.

• Sequences: Generate unique numbers.

• Stored Procedures: Precompiled SQL code that can be executed with parameters.