Author Question: A data warehouse database differs from an operational database because: A) data warehouse data ... (Read 122 times)

james · **on:** Jul 7, 2018

A data warehouse database differs from an operational database because:

A) data warehouse data are not stored in tables.
B) data warehouse databases do not have metadata.
C) data warehouse data are often stored in a dimensional database.
D) Both B and C
E) All of the above

Question 2

What are the four transaction isolation levels?

What will be an ideal response?

stanleka1 · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

C

Answer to Question 2

The four levels of isolation are Read Uncommitted, Read Committed, Repeatable Read, and Serializable. Read Uncommitted is the least restrictive, and it produces reads that are susceptible to dirty reads, nonrepeatable reads, and phantom reads. Read Committed isolation prevents dirty reads by only reading committed changes. Repeatable Read isolation prevents dirty reads and nonrepeatable reads. Serializable is the most restrictive level of isolation, and it prevents dirty reads, nonrepeatable reads, and phantom reads.