| List1 could be linked to the code table without causing row duplication. | Linking List1 to List2 will causing row duplication as neither list is unique. | ||||
| Code Table | <---> | List1 | <---> | List2 | |
| Jacob | Jayden | Jacob | Jaden appears two times in list one and three times in list two which will result in 3 records 2 times or six records being returned just due to links on the Jayden demormalized data. | ||
| Ethan | Ethan | Jacob | |||
| Michael | Michael | Michael | |||
| Jayden | Jayden | Jayden | |||
| William | William | William | |||
| Alexander | Alexander | Jayden | |||
| Noah | Noah | Jayden | |||
| Daniel | Daniel | Daniel | |||
| Aiden | Aiden | Aiden | |||
| Anthony | Anthony | Anthony |
Thursday, March 15, 2012
Joins on denormalized data vs. joins on unique code lists.
No comments:
Post a Comment