"Bi thing" data stream conversion--aggregation

Source: "Bi thing" data stream conversion--aggregation

The aggregation transformation can perform aggregation operations on the data like the function group by, Average, Minimum, Maximum, and Count in T-SQL. In the figure, you can see that the data is grouped in SampleID, and the Totalsugar does average, Maximum, Minimum, and count operations. This results in 4 columns of new data for other operations.

In the Aggregation Operations Editor Aggregate Transformation Editor, first select the column that needs to be aggregated, and then the selected column will appear in the following table, in the Output alias column, the alias of the input column. The most important setting is to select an aggregation operation in the Operation column. It has some options.

• GROUP BY: Group data by a column
• Average: Summing the data columns
• Count: Rows are calculated for non-empty rows in a set of data
• Count Distinct: Count distinct rows for non-empty rows in a set of data
• Minimum: The lowest value in a set of data columns
• Maximum: Calculate the maximum value for a number column in a set of data
• Sum: Sums a number column in a set of data

Click the Advanced tab interface to edit the conversion output in this interface. In the Advanced interface you can enter the name of the aggregation calculation and create a new column. In the Advanced tab interface, the most critical option is to set the conversion cache to make it at a suitable level. For example, the lower level is set to 500,000, the medium level is set to 5 million, and the higher level is set to 25 million. You can also use the number of keys property to set a specific value. The Auto Extend Factor property sets the amount of memory that the conversion can use, the default value is 25%, or you can set other options to guarantee RAM consumption. Warn on division The By Zero box is used to handle averaging when the divisor is 0, if there is no selection, the conversion fails will not give any hint.

"Bi thing" data stream conversion--aggregation