SharePoint Delegation with simple Filter on Text

[SPA]

I created a PowerApps Canvas app from scratch, and it has a  Drop Down box. For some reason I'm not able to perform a simple delegated filter against a SharePoint list. I have a SP list ("MMD") that only uses single-line-of-text, number, and date fields. The "PRG_MSA" field is a single line of text field in the "MSA" SP list. 

I have spent days searching online and making changes, trying to get it to delegate to SP, and all my research indicates the below code should not be a problem:

The Items property for the Drop Down control = Filter(MMD_Programs,PRG_MSA = varSelectedMSA)

I have also tried changing the text variable "varSelectedMSA" to a hard-coded text value. Tried changing "=" to "StartsWith" (even that would not work with the data I will eventually have). And I've tried loading the filter results into a collection for the heck of it. Despite changing the approach, the result is always the same...

I do not get any warning for delegation, but when I run the app, the number of items in the Drop Down is limited by whatever I set in the "Data row limit for non-delegable queries" setting. I changed this from 500 to 1, 2, and 3 to ensure I will not have delegation issues when we deploy at scale and we have more than 2000 items in the MSA SP list. Every time I change the Delegation row limit, I get exactly that many values returned.

If it is not delegating, why do I not get the non-delegation warning? More importantly, why am I only getting the non-delegated number of rows?

[juresti]

Hello,

I'm using a gallery in my post to do display the items without delegation affecting them.

The drop down control does not support this.

I think you could build a gallery into a pop up to use as a select list. If you needed to select multiple items at once it would require a little more work.

[Pstork1]

You are misunderstanding what the author is saying about changing the non-delegable setting.  Changing that setting will limit the maximum number of rows returned to whatever you change it to.  So if you set it to two you will only ever get two rows.  What the author of the article is suggesting is that changing that setting to something very low is a good way to check whether you have a delegation problem or not.  It is not a workaround for non-delegation.  There is no workaround for non-delegation.

[SPA]

I really do apologize for being slow to grasp a "simple" concept, but your post highlights the source of my confusion, @Pstork1

My understanding is that the setting limits returned matches to 1 ONLY IF the filter is Non-Delegable, but if the filter is delegable, then that limit would not be imposed (i.e., we'd be back to the 500 matches limit). In that case, it makes sense to set the setting to 1 so I would confirm delegation, by getting back more than one match (as per @juresti's post). After all, the setting tip says "Set how many rows are retrieved ... where delegation is not supported"

If the setting limits both delegated and non-delegated results returned as per your post ("...if you set it to two you will only ever get two rows..."), then why did @juresti 's post show a different result, and why would the MSFT Documentation suggest use of a setting of 1 to test delegation? I understand the setting does not get around Non-Delegation, but the filter I'm using should be delegable, and I ahould get all 5 matches even if the setting limits Non-Delegable results to 1. 

Where have I gone wrong in my thinking?

[SPA]

@juresti I will try changing to a gallery as you suggest

[Pstork1 · Accepted solution]

In the situation in the article that would be a correct understanding.  The problem is that when populating a dropdown through binding there is no delegation at all.  So you will always be limited to the non-delegable rate if you are populating a dropdown.  That's why @juresti is suggesting you switch to a gallery.

[SPA]

And THAT is what I needed to understand! I appreciate all the other posts and links (and will use the suggestions), but I hadn't heard the 500 limit using a DropDown was forcing delegation. Perhaps I'm the only one who didn't realize that. This information explains WHY I was having the issue and that's why I marked as the Solution. I would like to thank @juresti and @mdevaney for their help in understanding HOW to overcome the issue. And thank you all for your patience while I sussed it all out. 🙂