Amazon Web Services Ml Data Associate Interview Questions and Answers

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.

Cache is used for temporary storage of data in memory, while persist is used for saving data to disk for long-term storage.

• Cache is typically faster as it stores data in memory for quick access.

• Persist saves data to disk for durability and long-term storage.

• Cache is often used for temporary data that can be recomputed if lost, while persist is used for important data that needs to be retained.

• Examples: Using cache for ...read more

Reverse a sentence using Python

• Split the sentence into words using split() method

• Reverse the list of words using list slicing

• Join the reversed list of words back into a sentence using join() method

Surrogate key is a unique identifier used in databases to uniquely identify each record in a table.

• Surrogate keys are typically generated by the system and have no business meaning.

• They are used to simplify database operations and improve performance.

• Example: Using an auto-incrementing integer column as a surrogate key in a table.