Q1 · hard · AI-verified
In data warehousing, which schema design approach uses a central fact table surrounded by dimension tables in a star-like structure?
- Star Schema
- Snowflake Schema
- Galaxy Schema
- Constellation Schema
Q2 · hard · AI-verified
In SQL, which clause is used with aggregate functions to filter groups based on aggregate conditions after GROUP BY has been applied?
- FILTER
- HAVING
- CONDITION
- WHERE
Q3 · hard · AI-verified
Which SQL function returns the position of the first occurrence of a substring within a string, starting from a specified position?
- SUBSTRING
- PATINDEX
- LOCATE
- CHARINDEX
Q4 · hard · AI-verified
In a B+ tree index with order 5, what is the minimum number of keys that must be present in each internal node (except root)?
- 1 key
- 2 keys
- 3 keys
- 4 keys
Q5 · hard · AI-verified
Which database isolation level prevents dirty reads and non-repeatable reads but still allows phantom reads to occur?
- Read Uncommitted
- Read Committed
- Serializable
- Repeatable Read