pub fn partial_pushdown(quarb: &str) -> Option<Partial>Expand description
Attempt a partial pushdown: Some when the query’s leading row
predicates translate strictly and the rest of the query provably
cannot observe the filtering. The gates, each with its reason:
a single /table/* branch with no correlations (other shapes
address other data); only the leading run of expression
predicates pushes (a positional predicate before an expression
one sees unfiltered rows on the scan path); the table’s name
appears exactly once among the query’s steps (a second reach —
^-anchored subcontexts, self-references — would see the
filtered subset); no crosslink or resolution axes anywhere
(backlinks and reverse resolution into the table would too);
and no ::: / ;;; metadata anywhere (a filtered ;;;n-rows
would lie).