Struct TagPruner 

pub struct TagPruner<'a> { /* private fields */ }

One query’s view of the index, used to eliminate segments that cannot match its tag filters.

Why this answers “excluded” rather than “matching”

The index is derived state: it is updated after the catalog, from a segment’s series sidecar, and a segment can be in the catalog while the index has never heard of it — for the window between a compaction’s catalog swap and its index swap, and for as long as a sidecar cannot be read. A lookup that returns “the segments that match” cannot express that gap: everything it does not return is pruned, so a segment the index has not seen is indistinguishable from one it has seen and rejected.

Asking the opposite question makes the gap safe. Pruning happens only when the index holds the segment’s tag set and that set is missing a filtered pair, so an unindexed segment is scanned — slower, never wrong. This is the same rule the zone maps follow: a pruning structure may only ever fail towards more work.

Implementations

impl TagPruner<'_>

pub fn excludes(&self, segment_id: SegmentId) -> bool

Whether the index can prove that segment_id does not carry every filtered tag pair.

false whenever there are no filters, or the segment is not indexed.