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70-463 · Question #22

You are developing a SQL Server Integration Services (SSIS) package that imports data from a relational database to a data warehouse. You are importing data from a relational table named Projects…

The correct answer is D. Option D. When using Change Data Capture (CDC) and only the final state of each changed row is needed, the net changes CDC function is the correct choice because it collapses multiple operations on the same row into a single most-recent result.

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Question

You are developing a SQL Server Integration Services (SSIS) package that imports data from a relational database to a data warehouse. You are importing data from a relational table named Projects. The table has change data capture enabled on all columns. You need to process only the most recent values from rows that have been inserted or updated since the previous execution of the package. Which query should you use as the data source?

Exhibit

70-463 question #22 exhibit

Options

  • AOption A
  • BOption B
  • COption C
  • DOption D

How the community answered

(31 responses)
  • A
    10% (3)
  • B
    19% (6)
  • C
    3% (1)
  • D
    68% (21)

Why each option

When using Change Data Capture (CDC) and only the final state of each changed row is needed, the net changes CDC function is the correct choice because it collapses multiple operations on the same row into a single most-recent result.

AOption A

Option A does not use the net changes CDC function and would either return all intermediate change rows or miss the filtering needed to exclude stale intermediate updates.

BOption B

Option B likely uses cdc.fn_cdc_get_all_changes, which returns every individual change operation including intermediate updates, producing duplicate processing of the same row rather than only the most recent value.

COption C

Option C does not correctly filter for only inserted and updated rows within the appropriate LSN boundary range needed to capture changes since the previous package execution.

DOption DCorrect

Option D uses the cdc.fn_cdc_get_net_changes function, which returns only the net result of all changes to each row within the LSN range since the last package execution - for rows that were updated multiple times, only the latest version is returned, which satisfies the requirement to process only the most recent values for inserts and updates.

Concept tested: CDC net changes function for incremental SSIS data warehouse loads

Source: https://learn.microsoft.com/en-us/sql/relational-databases/track-changes/work-with-change-data-sql-server

Topics

#change data capture#CDC functions#incremental load#data source query

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