Rows

Number of rows accessed. This comes from the CARDINALITY column of the plan table. If appropriate, the number is converted to K (thousands), M (millions), or G (1000 millions, or billions).

Bytes

Number of bytes accessed. This is the value of the BYTES column of the plan table. If appropriate, the number is displayed in Kilobytes, Megabytes, or Gigabytes.

Cost

This is the value of the COST column of the plan table. If appropriate, the number is displayed in K (thousands), M (millions), or G (1000 millions, or billions). This column is not applicable to rule-based optimization