CIS 5450 - Midterm 1, 2025/2026 Actual complete comprehensive real exam questions and verified answers (Detailed & Elaborated) GRADED A+ /ACTUAL EXAM 2025 TEST 100% Solved 2025!!
The data in a relational database can be modeled as a graph of tuple relationships, as we saw in the slides. How do we traverse edges in this graph?
- ANSWER-joins
NoSQL systems are distinct from relational database management systems in which way? - ANSWER-they typically support key-based lookup of values
Hierarchical JSON data ("forests") may be faster to access from MongoDB, versus parsing a file into a dataframe and querying, for which reason? -
ANSWER-we can query for individual JSON trees
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We split hierarchical data into tables when... - ANSWER-the data has multiple values per parent item
We may want to use left outerjoins to reassemble hierarchical data because... - ANSWER-there may be parent items with no children
How many instructions can a typical machine run in one second, at peak? - ANSWER-billions
(10^9)
What does one-hot encoding refer to? - ANSWER-a scheme in which each categorical attribute gets its own Boolean column
Matrix bulk operations include what? - ANSWER-multiply, add, transpose, determinant, slice
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"Fancy indexing" refers to... - ANSWER-extracting rows from an array given a list of indexing
What is the t-test useful for testing? - ANSWER-how far the mean of a probability distribution differs from a reference, e.g., 0
If we test many hypotheses, we may wish to use the... - ANSWER-Bonferroni correction Line plots should only be used for which type of data? - ANSWER-continuous Data
When might we want to normalize our data? - ANSWER- when the overall trends are hard to spot due to differences in scale
The "grammar of graphics" counts data and its transformations into a visual
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