Chapter 7 Flashcards
1
Q
Does number of tables increases towards higher normalization and number of tables lesser towards denormalization
A
Yes
2
Q
What is de-normalization
A
It is not chaos, more like a controlled crash, with the aim of performance enhancement without loss of information.
3
Q
Why we do de-normalization in DSS
A
Performance
4
Q
Does de-normalization demands more storage space
A
Yes
5
Q
Do we do time series (collapse time, period) in de-normalization
A
Yes
6
Q
What is normal form of databases when values are atomic
A
1NF
7
Q
Does the database size increases in de-normalization
A
Yes
8
Q
What are 5 techniques of de-normalization
A
- Adding redundant columns
- Pre-joining
- Splitting table (horizontally or vertically)
- Collapse table
- Derived columns (summary, total)
