| A | B |
|---|
| COUNT | returns the number of rows with non-null values for the expression |
| SUM | calculates the sum ignoring null values. |
| MAX | returns the maximum value ignoring nulls. |
| aggregate | to gather into a sum or whole. |
| Group Functions | operate on sets of rows to give one result per group. |
| AVG | Calculates average value excluding nulls |
| NVL | Converts nulls to an actual value, or to force group functions to include null values. |
| DISTINCT | A command that suppresses duplicates, or makes the function consider only non-duplicate values within a column. |
| MIN | Returns minimum value ignoring nulls. |
| STDDEV | Calculates standard deviation ignoring null values. |
