As competition is growing all over the world in education, now companies want experts who can work for them for a specific task. Now, they just don’t want the degree but they want the skills too. In such a competition, people are trying to get skilled in one single field. One such skill is PostgreSQL. PostgreSQL is one of the best databases in the world nowadays. When it comes to open-source databases, it has occupied the second position in the world. If you are skilled in PostgreSQL and are going for the interview, then there are some of the questions you must prepare for this interview.
So here I am listing some of the questions for you: –
Q.1 How is a large table broken into smaller parts in PostgreSQL?
Ans. It’s called a table partition. What is a partitioned table in PostgreSQL? Ans. The partitioned table is a logical structure. It is used to share a large table. into smaller pieces called partitions.
Q2. What is pgadmin for in PostgreSQL?
Ans. The pgadmin in PostgreSQL is a data management tool. It is used to restore, develop, test, and manage databases.
Q.3 How can you avoid unnecessarily locking a database?
Ans. We can use MVCC (Multi-Version Concurrency Control) to avoid unnecessary locking of a database.
Q4. What is Python/PL?
Ans. PL/Python is a procedural language supported by PostgreSQL.
Q5. How do you drop the database in PostgreSQL?
Ans. We can drop the database using one of the following options:
- Using DROP DATABASE, an SQL command
- Using dropdb, an executable line command
Q.6 What Does a Schema Contain?
Ans. A schema contains tables as well as data types, views, indices, operators, sequences, and functions.
Q7. What are the different operators in PostgreSQL?
Ans. PostgreSQL operators contain arithmetic operators, comparison operators, logical operators, and bitwise operators.
Q8. Why indexes are used in PostgreSQL?
Ans. This is used by the search engine to quicken the retrieval.
Q9. What does a cluster index do?
Ans. The cluster index orders the rows of data in the table based on their key values.
Q10. What are the advantages of marking data types in columns when you create a table?
Ans. Some of these benefits include consistency, compactness, validation, and performance.
Q11. What should you do to update the statistics in PostgreSQL?
Ans. To update the statistics in PostgreSQL we need to use a special function called void.
Q12. What is the disadvantage of the DROP TABLE command when removing entire data from an existing table?
Ans. Although the DROP TABLE command has the ability to delete entire data from an existing table, the disadvantage is that it removes the entire structure of the table from the database. Because of this, we need to re-create a table to store data.
Q13. How can I delete all data from an existing table?
Ans. We can use the PostgreSQL TRUNCATE TABLE command to remove entire data from an existing table.
Q14. What are the features of a transaction in PostgreSQL? Which acronym do you use to refer to them?
Ans. The features of a transaction in PostgreSQL include atomicity, consistency, isolation, and durability, which are referred to as the acronym ACID.
Q15. What is the CTIDs field used for?
Ans. The CTID field identifies the specific physical rows in a table by their block and offsets the positions in that table.
Q16. Which commands are used to control transactions in PostgreSQL?
Ans. The commands to control transactions in PostgreSQL are BEGIN TRANSACTION. , COMMIT and ROLLBACK.
Q.17 How is SQL different from PostgreSQL?
Ans. PostgreSQL is an enhanced version of SQL.
Unlike SQL, views in PostgreSQL cannot be updated. Another difference is that SQL provides calculated columns. You can’t expect the same from PostgreSQL. Unlike SQL, PostgreSQL doesn’t require you to build a DLL to view the code you’re running. PostgreSQL supports dynamic actions, SQL does not.