Selective overwrite on Partition and Liquid clustered tables

RGSLCA
New Contributor II

Hi,

I have created 2 identical tables but one is partitioned and the one is a Liquid Clustered with Auto Clustering.

I inserted 30M rows x 2 (60M) for two dates , date 1 = 2026-06-01 and date = 2026-06-02 , then I overwrite the date 2026-06-02 with a selective overwrite statement 

REPLACE USING (BED)

For partition table , history shows ,

operationParameters 
 

object

  • mode
    "Overwrite"
  • statsOnLoad
    "false"
  • partitionBy
    "[]"
operationMetrics 
 object
  • numFiles
    "43"
  • numRemovedFiles
    "43"
  • numRemovedBytes
    "6090798096"
  • numDeletionVectorsRemoved
    "0"
  • numOutputRows
    "30000000"
  • numOutputBytes
    "6101142740"

For Liquid Clustered table 

operationParameters 
 object
  • partitionBy
    "[]"
  • clusterBy
    "[]"
  • mode
    "Overwrite"
  • clusteringOnWriteStatus
    null
  • statsOnLoad
    "false"
  • replaceUsingCols
    "(BED)"
operationMetrics 
 object
  • numFiles
    "43"
  • numRemovedFiles
    "43"
  • numRemovedBytes
    "5779903887"
  • numCopiedRows
    "0"
  • numDeletionVectorsAdded
    "0"
  • numDeletedRows
    "30000000"
  • numDeletionVectorsRemoved
    "0"
  • numAddedChangeFiles
    "0"
  • numOutputRows
    "30000000"
  • numOutputBytes
    "5779715681"
     

Its overwriting 43 files (Total 86) ?, is this optimal ?

Is there a way to improve performance by reducing the # of files ?

I am using 

INSERT INTO <target>  REPLACE USING (col) 

SELECT <cols> FROM <table>