Expand description
Metadata Cache — in-memory cache for segment metadata.
Caches segment headers, bloom filters, and column statistics permanently in memory. Updated on segment creation, compaction, and deletion. Memory cost is approximately 1 KB per segment — no eviction needed.
§Eviction policy
This cache intentionally has no LRU eviction. Each entry is ~1 KB
(header + column stats), so even 100 000 segments consume only ~100 MB.
Segments are explicitly removed from the cache when they are deleted or
compacted away (see MetadataCache::remove). If segment counts ever
grow to the point where this becomes a concern, an LRU bound or
generation-based eviction can be layered on top.
Structs§
- Cached
Segment Meta - Cached metadata for a single segment.
- Metadata
Cache - In-memory metadata cache for all segments.