Computes the rolling count of non-null values forward or backward of the current row within the specified column.

For more information on a non-rolling version of this function, see COUNTA Function.

Column example:

rollingcounta(myCol)

Output: Returns rolling count of non-null values in the myCol column.

Rows before example:

rollingocounta(myNumber, 3)

Output: Returns the rolling count of non-null values of the current row and the three previous row values in the myNumber column.

Rows before and after example:

rollingcounta(myNumber, 3, 2)

Output: Returns the rolling count of non-nulls from the three previous row values, the current row value, and the two rows after the current one in the myNumber column.     

rollingcounta(col_ref, rowsBefore_integer, rowsAfter_integer) order: order_col [group: group_col]


ArgumentRequired?Data TypeDescription
col_refYstringName of column whose values are applied to the function
rowsBefore_integerNintegerNumber of rows before the current one to include in the computation
rowsAfter_integerNintegerNumber of rows after the current one to include in the computation

For more information on the order and group parameters, see Window Transform.

col_ref

Name of the column whose values are used to compute the function. 

Required?Data TypeExample Value
YesString (column reference to Integer or Decimal values)myColumn

rowsBefore_integer, rowsAfter_integer

Integers representing the number of rows before or after the current one from which to compute the rolling function, including the current row. For example, if the first value is 5, the current row and the five rows before it are used in the computation. Negative values for rowsAfter_integer compute the rolling function from rows preceding the current one.

Required?Data TypeExample Value
NoInteger4

Example - Counting messages

In the following example, messages are tabulated every 10 seconds from a system. If no message is generated, null values are returned. 

Source:

TimestampmsgTypemsgDescription
15:10:00 PMwarningServer restarted.
15:10:10 PMwarningUnable to locate patterns file.
15:10:20 PM

15:10:30 PM

15:10:40 PMerrorCannot connect to data source.
15:10:50 PMerrorCannot open dataset.
15:11:00 PM

15:11:10 PM

15:11:20 PMerrorInsufficient permissions to write to target location.
15:11:30 PM

15:11:40 PMwarningServer restarted.
15:11:50 PMwarningUnable to locate patterns file.
15:12:00 PMerrorData node offline.
15:12:10 PM

15:12:20 PM

15:12:30 PMwarningInvalid statement in recipe.
15:12:40 PM

15:12:50 PM

Transformation:

You are interested in counting the number of entries for the preceding minute for each row. You add the following:


Results:

TimestampmsgTypemsgDescriptionrollingcounta_msgType
15:10:00 PMwarningServer restarted.1
15:10:10 PMwarningUnable to locate patterns file.2
15:10:20 PM

2 
15:10:30 PM

15:10:40 PMerrorCannot connect to data source.3
15:10:50 PMerrorCannot open dataset.4
15:11:00 PM

15:11:10 PM

15:11:20 PMerrorInsufficient permissions to write to target location.3
15:11:30 PM

3 
15:11:40 PMwarningServer restarted.3
15:11:50 PMwarningUnable to locate patterns file.3
15:12:00 PMerrorData node offline.4
15:12:10 PM

4 
15:12:20 PM

3 
15:12:30 PMwarningInvalid statement in recipe.4
15:12:40 PM

3 
15:12:50 PM

2