Reply To: FacetWP & Custom Tables

I don't know if this is helpful.
"When the “Re-index” button is clicked, FacetWP first retrieves all post IDs that should be indexed. It uses WP_Query, and the query arguments are customizable.
FacetWP then loops through the array of post IDs. For each, it loops through all available facets and saves applicable values."
https://facetwp.com/how-facetwps-indexer-works/
https://facetwp.com/documentation/facetwp_indexer_query_args/