Course Notes
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-- A sample query for you to replace!
SELECT
*
FROM booksQ1. What is OLTP vs OLAP ? Q2. What is a Schema ?( Blueprint for the data coming into the database) Q3. What is a data warehouse and where is it most commonly seen ? --> Q4. What are the features of a Data Warehouse? [ 1. Optimized for Analytics, 2. Usually read only 3. Data from multi-sources] Q5. What are Data Marts? Q6. Different types of Warehouses available ? -- Amazon ( Redshift) , Azure ( SQL) , Google (BigQuery) Q7. What is a Data Lake ? -- Massive amounts of data -- in PB Q8. What is Schema on read Vs Schema on write ? Q9. What is ELT vs ETL ? Q10. Different types of Data Modelling : 1. Conceptual -- ER Diagrams , UMLs 2. Logical -- DataBases and Schemas/ Relational Models / Star Schemas 3. Physical -- CPUs, Partions, Indexes, Tablespaces Q11. What is Dimensional Modelling? 1. It is form of Data model generally used in OLAP systems. 2. It uses things like a Star Schema 3. Star Schema -- Is made using Fact Tables| Dimension Tables
Star Schema :: Dimensional Model -- 1. Q12. What is the difference between Star Schema and Snowflake Schema -- Star schema generally extends to one dimension, but Snowflake extends to multiple level of dimension Also, in Snowflake the dimensions may be normalized ..
Q13. What is Normalization ? --