How do I create a composite index for my Firestore query? - node.js

Question

I'm trying to perform a firestore query on a collection which results in a failure because an index needs to be created for the query I'm attempting. The error contains a link that is suppose to auto create the missing index for me. However when I follow the link and attempt to create the index that has been prepared for me I encounter an error stating "name only indexes are not supported". I would also point out I have been using the npm functions-framework to test my cloud function that contains the relevant query.
I have tried creating the composite index myself manually but none of the index I have made seem to satisfy my attempted query.
Sample docs in my Items Collection:
{
descriptionLastModified: someTimestamp <a timestamp datatype>
detectedLanguage: "en-us" <string>
}
{
descriptionLastModified: someTimestamp <a timestamp datatype>
detectedLanguage: "en-us" <string>
}
{
descriptionLastModified: someTimestamp <a timestamp datatype>
detectedLanguage: "fr" <string>
}
{
descriptionLastModified:someTimestamp <a timestamp datatype>
detectedLanguage: "en-us" <string>
}
These are all queries I have tried which fail:
let queryRef = itemsRef.where('descriptionLastModified','<=', oneDayAgoTimestamp).orderBy("descriptionLastModified","desc").where("detectedLanguage", '==', "en-us").get()
let queryRef = itemsRef.where('descriptionLastModified','<=', oneDayAgoTimestamp).where("detectedLanguage", '==', "en-us").get()
let queryRef = itemsRef.where("detectedLanguage", '==', "en-us").where('descriptionLastModified','<=', oneDayAgoTimestamp).get()
I have made the following composite indexes at the collection level to no avail:
CollectionId:items Fields: descriptionLastModified:DESC detectedLangauge: ASC
CollectionId:items Fields: descriptionLastModified:ASC detectedLangauge: ASC
CollectionId:items Fields: detectedLangauge: ASC descriptionLastModified:DESC
My expectation is I should be able to filter my items by their descriptionLastModified timestamp field and additionally by the value of their detected Language string field.

Answer 1

In case anyone finds this in the future, its 2021, I still find composite indexes created manually, despite being incredibly simple, or you'd think and I fully understand why the OP thought his indexes would work, often just don't. Doubtless there is some subtlety that reading some guides would make clear but I haven't found the trick yet and have been using firestore for over 18 months intensively at work.
The trick is to use the link it creates, but this often fails, you get a dialogue box telling you an index will be created, but no details for you to manually create and the friendly blue 'create' button does nothing, it neither creates the index nor does it dismiss the window.
For a while I had it working in firefox but it stopped. A colleague across a couple of desks who has to create them a lot tells me that Edge is the most reliable, and you have to be very careful to not have multiple google accounts signed in - if edge (or chrome) takes you to the wrong login initially when following the link, even if you switch user back (and you have to do this because it will assume your default login rather than say the one currently selected in your only google cloud console window), even if you switch back its about a 1 in 3. He tells me in edge it works about 60%
I used to get about 30% with firefox just hitting refresh and soon a few times, but cant get it working other than in edge now, and actually, unless there is a client with little cash who will notice, I just go for inefficient and costly queries which return the superset of results and do some filters on the results. Mostly running in nodejs and its nippy enough for my purposes. Real shame to ramp up the read counts and consequential bills, but just doesn't seem a fix.