Oracle 1z0-184-25 Questions Answers

Euclidean Squared Distance (L2-squared) skips the square-root step of Euclidean Distance (L2), i.e., ∑(xi - yi)² vs. √∑(xi - yi)². Since the square root is monotonic, ranking order remains identical, but avoiding it (C) reduces computational cost, making queries faster—crucial for large-scale vector search. It’s not the default metric (A); cosine is often default in Oracle 23ai. It doesn’t relate to partitioning (B), an indexing feature. Accuracy (D) is equivalent, as rankings are preserved. Oracle’s documentation notes L2-squared as an optimization for performance.

Finding the closest matching sentences across books involves comparing a query vector to sentence vectors stored in a table (e.g., columns: book_id, sentence, vector). A nested query with ORDER BY (A) is the optimal SQL structure: an inner query computes distances (e.g., SELECT sentence, VECTOR_DISTANCE(vector, :query_vector, COSINE) AS score FROM sentences), and the outer query sorts and limits results (e.g., SELECT * FROM (inner_query) ORDER BY score FETCH FIRST 5 ROWS ONLY). This ranks sentences by similarity, leveraging Oracle’s vector capabilities efficiently, especially with an index.

Option B (exact search) describes a technique, not a structure, and a full scan is slow without indexing—lacking specificity here. Option C (GROUP BY) aggregates (e.g., by book), not ranks individual sentences, missing the “closest” goal. Option D (FETCH PARTITIONS BY) isn’t a valid clause; it might confuse with IVF partitioning, but that’s index-related, not query syntax. The nested structure allows flexibility (e.g., adding WHERE clauses) and aligns with Oracle’s vector search examples, ensuring both correctness and scalability—crucial when books yield thousands of sentences.

In Oracle 23ai, EFCONSTRUCTION (A) controls the number of closest vector candidates (edges) considered during HNSW index construction, affecting the graph’s connectivity and search quality. Higher values improve accuracy but increase build time. VECTOR_MEMORY_SIZE (B) sets memory allocation, not candidate count. NEIGHBOURS (C) isn’t a parameter; it might confuse with NEIGHBOR_PARTITIONS (IVF). TARGET_ACCURACY (D) adjusts query-time accuracy, not index creation. Oracle’s HNSW documentation specifies EFCONSTRUCTION for this purpose.

Approximate similarity search (ANN) in Oracle 23ai (B) uses indexes (e.g., HNSW, IVF) to trade accuracy for speed, returning near-matches faster by not comparing all vectors. Exact search compares every vector (A), not ANN. It doesn’t guarantee 100% accuracy (C); that’s exact search. It’s faster, not slower (D), than exact search due to indexing. Oracle’s documentation defines ANN’s speed-accuracy trade-off as its hallmark.