GREATEST


Returns the maximum value from many columns. This is similar to MV_MAX
except it’s intended to run on multiple columns at once.
```esql
ROW a = 10, b = 20
| EVAL g = GREATEST(a, b)
```

When run on keyword or text fields, this’ll return the last string
      in alphabetical order. When run on boolean columns this will return
      true if any values are true.
Supported types:
