Free sections from Ultra Transcenders DP-900: Microsoft Azure Data Fundamentals, on the comparisons and decisions the exam keeps asking about.
What each ACID property guarantees in a transactional (OLTP) database, with the classic funds-transfer example.
How extract-transform-load and extract-load-transform differ, and why ELT is common in modern lakehouses.
How OLTP and analytical systems differ in purpose, data shape, queries and users.
How normalisation splits data into one table per entity, linked by keys, so each fact is stored once.
The three Azure SQL options side by side: IaaS or PaaS, compatibility, management and availability.
Which Azure SQL option or open-source database service fits a requirement, and why.
Storage and access costs, minimum retention periods, Archive rehydration and lifecycle management policies.
The key characteristics of Azure Cosmos DB: schema-agnostic items, automatic indexing, global distribution and low latency.