Quick preparation of Database Concepts for Interviews

Quick preparation of Database Concepts for Interviews

20 April, 2022

The most critical Concepts to know about databases for Interviews. Learn database concepts and prepare for your database job interview with this interview preparation guide.

ACID—database(of database transaction):

  • ATOMICITY — all transactions' operations are all successful or failed, not an intermediate state.
  • CONSISTENCY — each transaction guarantees that data is in the updated state (strong consistency), (eventual consistency) will be updated after some time.
  • ISOLATION — execution of multiple transactions will be the same as they are executed sequentially.
  • DURABILITY — transactions are in the non-volatile state, they can not crash

Relational database— database organized in tables, rows, and columns, and their relation.

Nonrelational database— NOT tabular, specially organized for specific purposes.

SQL— structured query language;

SQLdatabase —arelational database that supports SQL;

NoSQL— a database that does not support SQL

Database index—adata structure that improves the data retrieval, and slows the data writing (because create an index for columns);

Strong consistency— relates to ACID. (every transaction guarantee updated data) — PostgreSQL;

Eventual consistency— (transaction will eventually (later) know the updated data);