DEA-C02 Data Movement Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Unload with FILE_FORMAT = (TYPE = PARQUET COMPRESSION = SNAPPY).

  Why this is correct

  Parquet is a columnar format that applies per-column encodings such as dictionary and run-length encoding, which greatly shrink columns with many repeated values, and SNAPPY adds block compression on top. This yields the smallest transfer volume while remaining readable by common analytics and ML tools.

• ✗

  Unload with FILE_FORMAT = (TYPE = JSON COMPRESSION = GZIP).

  Why it's wrong here

  JSON stores each value with its key name repeated in every record, which inflates the raw payload, and GZIP cannot recover that overhead. For a wide table with many repeated values, JSON output is usually substantially larger than a columnar format and is also slower for downstream tools to parse.

• ✗

  Unload with FILE_FORMAT = (TYPE = CSV COMPRESSION = GZIP).

  Why it's wrong here

  CSV with GZIP does compress the data, but because CSV is row-oriented and stores repeated values verbatim in every row, it cannot exploit the repetition across rows nearly as well as a columnar format with dictionary encoding. The resulting files are typically much larger than Parquet for low-cardinality columns.

• ✗

  Increase MAX_FILE_SIZE so fewer, larger files are produced.

  Why it's wrong here

  MAX_FILE_SIZE controls how the unloaded rows are split into files; it does not change the encoding or compression of the content. Producing fewer, larger files may reduce per-file overhead slightly, but it will not achieve the significant size reduction that columnar encoding and compression provide.