DB interview questions
DB
- Czy kazdy system SQL implementuje standard SQL w jednakowy sposób?
- Podaj róznice pomiedzy tabela a perspektywa
- Jaka jest glówna róznica miedzy systemami SQL a NoSQL?
- Czym jest transakcja?
- Czym jest ACID?
- What transaction isolation levels do you know?
- Primary key vs unique key. Differences.
- What types of constraints does one know?
- What is a view/materialized view.
- What kind of joins do you know?
- What is the difference between inner join and outer join?
- Types of tables (regular, temporary, index-organized etc)
- Are database Indexes useful? What is the role of them?
- Why many indexes are not good for performance
- Views, why they are needed?
- Which of SELECT, UPDATE, DELETE, ADD’s performance is mostly affected by performance of indexes?
- What does it mean database de-normalization?
- What are ways to increase performance of database
SQL (Oracle applied)
- What are DML and DDL
- Aggregate functions with examples
- What is a nested subquery?
- Types of indices in Oracle
- What is a hierarchical query? How to create it?
- What is a bitmap index
- Partitioning and methods of partitioning