Performance Issue with "FROM" query (maybe not a bug)

[efirlus]

What happened?

No big deal, my vault has 8 directories, and I use a query that watches 3 of them and lists “documents created today”.

The key point is that for each additional folder, I do a FROM -“Adir” -“Bdir” and so on.

I don't know when, but roughly around 4000 documents, Obsidian started to get really heavy.
After 6000, I had to turn off dataview altogether on mobile.

I just found a solution, but I'm not a programmer so I don't know the exact cause.

In conclusion, FROM “6” AND “7” AND “8” is much more pleasant than FROM -“1” AND -“2”.... AND -“5”
Maybe there's something wrong with the part that handles the - that I'm not aware of.

DQL

TABLE dateformat(file.mtime, "HH:mm:ss") as Time, tags
FROM "3. Project" AND "4. Storage" AND "5. Article"
WHERE file.mday = this.file.day
SORT file.mtime desc

JS

No response

Dataview Version

0.5.67

Obsidian Version

1.7.6

OS

Windows

[holroy]

Doing FROM "A" vs FROM -"B" is vastely different from a programming point of view. Imagine having 100 files in each of the folders from "A" through "Z" (so a total of 2700 files). The first variant checks the file lists, and continue the query only looking at the 100 files from the "A" folder. The second variant checks the entire file list, eliminates the 100 files from "B", and continues to look at the remaining 2600 files.

So in the first case, the WHERE clause looks at a 100 files, and in the second it looks at 2600 files. So if you're able to, you should always limit the FROM as much as possible to reduce the load for the rest of the query.