Understand Delta Optimization Techniques, Such as Deletion Vectors and Liquid Clustering. DATA-ENGINEER-PROFESSIONAL Practice Questions (Page 5)

Questions 21–25

1. 21foundation · easy

   Which SQL clause is used to enable liquid clustering on a new Delta table?

   • AORDER BY
   • BGROUP BY
   • CCLUSTER BY
   • DPARTITION BY
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2. 22foundation · easy

   How does liquid clustering differ from traditional partitioning?

   • ALiquid clustering requires a fixed schema, while partitioning does not
   • BLiquid clustering allows clustering keys to be changed without rewriting the entire table
   • CLiquid clustering stores data in a columnar format, while partitioning uses row format
   • DLiquid clustering is only for small tables, while partitioning is for large tables
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4. 23foundation · easy

   What is a known trade-off of using deletion vectors?

   • AThey require the table to be partitioned
   • BThey can degrade read performance because readers must apply the vector to filter rows
   • CThey prevent the use of OPTIMIZE on the table
   • DThey increase the size of the data files
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5. 24foundation · easy

   Which type of query benefits most from liquid clustering?

   • AQueries that filter on the clustering keys
   • BQueries that only insert new data
   • CQueries that aggregate the entire table without filters
   • DQueries that update a single row
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6. 25foundation · easy

   Which table property enables deletion vectors in Delta Lake?

   • Adelta.deletionVectors.enabled = true
   • Bspark.databricks.delta.deletionVectors = true
   • Cdelta.columnMapping.mode = 'deletion'
   • Ddelta.enableDeletionVectors = true
   Reveal Solution Discussion Select an answer first