DY0-001 Exam Dumps : CompTIA DataX Exam

→ A LEFT JOIN ensures all rows from Table 1 (Top Movies) are preserved, even if there’s no matching actor data in Table 2. This matches the requirement to show all movies, enriched with actor information when available.

Why the other options are incorrect:

A: INNER JOIN would exclude movies without matching actor entries.

B: UNION combines distinct rows — not appropriate for matching columns between two tables.

C: INTERSECT shows only common movies — excludes unmatched top movies.

Official References:

CompTIA DataX (DY0-001) Study Guide – Section 5.2:“LEFT JOINs are used when all records from one table (primary) must be retained, even if there are no matching rows in the secondary table.”

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→ Linear Discriminant Analysis (LDA) is a supervised classification method used to predict a categorical target (such as travel destination) based on multiple input features. It models decision boundaries between classes — which is appropriate when predicting a fixed set of destinations.

Why the other options are incorrect:

B: k-means is unsupervised and doesn't use labeled output like travel destination.

C: Latent Semantic Analysis is used for extracting relationships from textual data — not categorical prediction.

D: PCA reduces dimensionality but doesn’t classify.

Official References:

CompTIA DataX (DY0-001) Official Study Guide – Section 4.1:“Linear Discriminant Analysis is used when the response variable is categorical and the objective is classification.”

Classification Techniques Guide, Chapter 7:“LDA excels in multi-class prediction when the input data is continuous and the output is a known category.”

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→ In real-time systems, low latency (short run time) is critical. While the Artificial Neural Network provides the highest accuracy, its 12-minute runtime makes it unsuitable for real-time inference. Random forest is the fastest but offers the lowest accuracy.

XGBoost provides an excellent balance between runtime (5 minutes) and accuracy (90%). It’s well-optimized for performance and scalability, and thus is a strong candidate for real-time classification when balancing both efficiency and predictive quality.

Why the other options are less ideal:

B: Random forest is faster but significantly less accurate.

C: Decision trees have longer run time than XGBoost with only a 2% accuracy improvement.

D: Artificial neural network has the highest accuracy but is too slow for real-time applications.

Official References:

CompTIA DataX (DY0-001) Official Study Guide – Section 4.3:“In real-time applications, model selection involves a trade-off between accuracy and inference speed. XGBoost offers competitive accuracy with efficient runtime.”

Machine Learning Systems Design Guide, Chapter 7:“XGBoost is well-suited for real-time systems due to its balance of model complexity and fast prediction times.”

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