*** Single column partition key ***
<rows_read>4</rows_read>
<rows_read>3</rows_read>
<rows_read>1</rows_read>
*** Composite partition key ***
<rows_read>0</rows_read>
<rows_read>6</rows_read>
<rows_read>0</rows_read>
<rows_read>3</rows_read>
<rows_read>0</rows_read>
<rows_read>6</rows_read>
<rows_read>3</rows_read>