Creates a comparison level that matches when the smaller of two array columns is a complete subset of the larger. In other words, every element of the smaller array appears in the larger one.
Value
A comparison-level object for use in il_compare().
Details
On DuckDB this is computed in SQL by counting the distinct elements shared by both arrays. On SQLite it falls back to an R-side set check.
Examples
il_spec() |>
il_compare(qualifications, cl_array_subset())
#> Linkage Specification
#> Comparisons (1):
#> qualifications : array_subset
#> Blocking rules: (none)