Every time you run a KPIBees query there is an associated credits cost for that particular run. This cost is decided by the type of connector and the number of rows returned.
For example, if you run a CSV query it will cost:
1 Credit if the output has less than 100 rows
2 Credits if the output has less than 1 K rows
3 Credits if the output has less than 10 K rows
5 Credits if the output has less than 100 K rows
20 Credits if the output has less than 1 Mil. rows
In the table below, you can see the associated cost for each connector and output size. Please note that other connectors will cost more than others. For example, MySQL costs 2 Credits for outputs less than 100 rows.
Some connectors will cost more than others because there is a cost implied to connecting to an external service. For example, it's more costly to retrieve data from a Google API than it is to retrieve raw data from a raw JSON API.
The number of columns in the output does not affect the cost - only the rows are counted.
Even if a query might return the same result on consecutive runs, the credits will still be deducted - we have no way of knowing that a query has returned the same result or not. Also, if your query returns nothing on a particular run, it will still be charged.
The Query Credits will reset back 0 on the 1st of each calendar month.
To check how you used your credits in the current month, go "Add-ons", then KPIBees, then click on "Premium".
Then select the "Credit Usage Logs" tab to get the full picture.