Skip to content

Tag: data-warehouse

Three-table join with NO EXISTS

I have three tables and would like to answer the following question in SQL: “Who has only certifications that do NOT have scores?” For instance, in the setup below, the query would return “John” only. Joana has the “AWS Certification”, which is in SCORE table (id 57). Marry has the “ITIL V3 Certification” which is not in the SCORE table,

Using Identity or sequence in data warehouse

I’m new to data warehouse, So I try to follow the best practice, mimicking some implementation details from the Microsoft Demo DB WideWorldImportersDW, One of the things that I have noticed is using Sequence as default value for PK over Identity. Could I ask, If it’s preferable to use Sequence over Identity in data warehouse in general and Which one