Forum Discussion
Restrict records to current year
Hello John,
I will have to be careful with my answer because when you say "sends only...query to source" the precise answer, in general, depends on whether query folding occurs. However the precise answer may not matter to you if you're only interested in the "bottom line" result - i.e. will the query return records for the current year...the answer is "yes".
To go back to the precise answer, some sources, such as SqlServer can carry out filtering before returning a result. If this is the case Power Query will delegate filtering to the source and send a query to the source asking it to return filtered results.
If a source cannot carry out filtering (e.g. an Excel file), Power Query will fetch and scan the source line by line to do the filtering. In this case the query is not "sent" but the result is still filtered.
You can read more about query folding here.
Hope this helps.
Thank you so much for the information, really helpful.
One last thing to check. Say I have the following file:
Now using the M-language I filtered for current year which is 2023. If I do filtering (Filter rows from the UI) for 2023 instead of M-language, the process is same correct?
And I understand the query folding. In this case, Power BI brings all the data to memory and then filters the data for 2023.
| LocID | Location | Date | AgeGrp | PopMale | PopFemale | PopTotal |
| 5 | Antigua and Barbuda | 1/4/2015 | 0-4 | 3.543 | 3.436 | 6.979 |
| 6 | Argentina | 1/5/2022 | 0-4 | 1836.187 | 1769.816 | 3606.003 |
| 7 | Armenia | 1/6/2023 | 0-4 | 107.368 | 93.715 | 201.083 |
| 8 | Aruba | 1/7/2023 | 0-4 | 3.402 | 3.257 | 6.659 |
| 9 | Australia | 1/8/2023 | 0-4 | 750.45 | 711.435 | 1461.885 |
| 10 | Austria | 1/9/2023 | 0-4 | 200.53 | 190.404 | 390.934 |
| 11 | Afghanistan | 1/10/2023 | 0-4 | 2715.07 | 2600.535 | 5315.605 |
| 12 | Albania | 1/11/2023 | 0-4 | 92.622 | 81.239 | 173.861 |
| 13 | Algeria | 1/12/2023 | 0-4 | 1966.415 | 1885.869 | 3852.284 |
| 14 | Angola | 1/13/2023 | 0-4 | 2233.041 | 2239.035 | 4472.076 |
| 15 | Antigua and Barbuda | 1/14/2023 | 0-4 | 3.543 | 3.436 | 6.979 |
| 16 | Argentina | 1/15/2023 | 0-4 | 1836.187 | 1769.816 | 3606.003 |
| 17 | Armenia | 1/16/2023 | 0-4 | 107.368 | 93.715 | 201.083 |
| 18 | Aruba | 1/17/2023 | 0-4 | 3.402 | 3.257 | 6.659 |
| 19 | Australia | 1/18/2023 | 0-4 | 750.45 | 711.435 | 1461.885 |
| 20 | Austria | 1/19/2023 | 0-4 | 200.53 | 190.404 | 390.934 |