nerdexam
Microsoft

70-463 · Question #53

You develop a SQL Server Integration Services (SSIS) package that imports SQL Azure data into a data warehouse every night. The SQL Azure data contains many misspellings and variations of abbreviation

The correct answer is C. Change the similarity threshold to 0.85.. Raising the Fuzzy Lookup similarity threshold from 0.50 to 0.85 forces the transformation to require closer string matches, reducing incorrect matches without the performance cost of enabling exhaustive search.

Extract and transform data

Question

You develop a SQL Server Integration Services (SSIS) package that imports SQL Azure data into a data warehouse every night. The SQL Azure data contains many misspellings and variations of abbreviations. To import the data, a developer used the Fuzzy Lookup transformation to choose the closest- matching string from a reference table of allowed values. The number of rows in the reference table is very large. If no acceptable match is found, the Fuzzy Lookup transformation passes a null value. The current setting for the Fuzzy Lookup similarity threshold is 0.50. Many values are incorrectly matched. You need to ensure that more accurate matches are made by the Fuzzy Lookup transformation without degrading performance. What should you do?

Options

  • AChange the Exhaustive property to True.
  • BDecrease the maximum number of matches per lookup.
  • CChange the similarity threshold to 0.85.
  • DIncrease the maximum number of matches per lookup.

How the community answered

(28 responses)
  • A
    7% (2)
  • B
    7% (2)
  • C
    82% (23)
  • D
    4% (1)

Why each option

Raising the Fuzzy Lookup similarity threshold from 0.50 to 0.85 forces the transformation to require closer string matches, reducing incorrect matches without the performance cost of enabling exhaustive search.

AChange the Exhaustive property to True.

Setting the Exhaustive property to True forces the transformation to compare every input row against every row in the reference table, which would degrade performance significantly - explicitly ruled out by the requirement.

BDecrease the maximum number of matches per lookup.

Decreasing the maximum number of matches per lookup controls how many candidate matches are returned per row but does not raise the quality bar for what qualifies as a match, so it does not reduce incorrect matches.

CChange the similarity threshold to 0.85.Correct

The similarity threshold in the SSIS Fuzzy Lookup transformation controls the minimum similarity score (0 to 1) a candidate match must achieve to be returned. Increasing it from 0.50 to 0.85 means only strings that are 85% or more similar to a reference value will be accepted, directly reducing false positives. This change improves accuracy without enabling the Exhaustive property, which would scan every index row and severely degrade performance on a large reference table.

DIncrease the maximum number of matches per lookup.

Increasing the maximum number of matches per lookup returns more candidates per row, which would introduce more potential incorrect matches rather than fewer.

Concept tested: SSIS Fuzzy Lookup similarity threshold tuning for accuracy

Source: https://learn.microsoft.com/en-us/sql/integration-services/data-flow/transformations/fuzzy-lookup-transformation

Topics

#Fuzzy Lookup#similarity threshold#data cleansing#transformation

Community Discussion

No community discussion yet for this question.

Full 70-463 Practice