federated-planning

Cost-based federated SPARQL source selection + bind-vs-hash join planning over already-fetched source descriptors, plus an ANAPSID-style non-blocking streaming join with operator spill, via the opt-in sparq-fedplan crate. Use when planning a federated BGP across multiple SPARQL endpoints from their served statistics (VoID property/class partitions + mined scs: characteristic sets): deciding which sources can contribute to each triple pattern (HiBISCuS recall-safe pruning + CostFed skew-aware cardinality), choosing a join order with per-join bind-vs-hash-vs-streaming algorithm selection (characteristic-set star cardinality for intermediate sizes), and executing a memory-bounded non-blocking symmetric hash join over incrementally-arriving sub-results (StreamJoin, spill to a backing store, result multiset-equal to a blocking join). Pure + deterministic planning, no network I/O. Off by default; does not touch sparq-core/sparq-engine's lean build. Also covers live adaptive RE-planning at stage boundaries (mid-execution plan switching when observed cardinalities diverge from estimates, or when a source is observed to be slow — per-source EWMA-smoothed latency is folded into the cost model as a documented heuristic bias toward faster sources, smoothing out transient spikes) via the further opt-in adaptive-replan feature (AdaptiveExecutor) — sound because BGP join is order-independent (latency changes ordering/cost only, never results), with mid-operator swap + live source failover deferred.