SQL pattern · 5 problems

Slowly-changing dimensions

Graded problems on slowly-changing dimensions, from easy to hard.

5 problems · about 1 h 20 min in all
Start with problem 01Type-1 current snapshot from a change log · 12 min

Easy

2 problems · about 20 min
01Type-1 current snapshot from a change log12 min →02Distinct email versions per customer8 min →

Medium

1 problem · about 14 min
03Detect which attribute changed per version14 min →

Hard

2 problems · about 42 min
04Build SCD Type 2 history from a change log22 min →05Point-in-time lookup over SCD2 history20 min →