Performance RE List Expressions - isblank/isnotblank vs count

[Markus_Malessa]

I have many instances across several applications where I might filter/select from a table and then have to see if the filtering returns records or not, or do the same on REF_ROWS based on a relationship within a Virtual Column.

I was hoping that someone might have statistical data or performed other analysis that would indicate if a isblank/isnotblank or count>0/count=0 expression performs better within the confines of AppSheet?

[Marc_Dillon]

Isblank for sure. That's common across all languages that I know, no reason it'd be any different here. No statistical evidence, beyond what you could probably find by googling this in context of other systems, but if you want some logic for it: a count would count the entire set, whereas an isblank would be able to stop after seeing, or not seeing, the first element.