omnigraph/docs
Ragnor Comerford 787d41ec5f
feat(engine): cost-based Expand dispatch chooser (C5)
Replace the fixed frontier<=1024 && hops<=6 dispatch threshold with a pure,
IO-free cost model. choose_expand_mode compares the indexed path's
frontier-relative work (hops * frontier * fanout, or hops * |E| when BTREE
coverage is degraded) against the cost of building the whole-graph CSR
(BUILD_FACTOR * |E|), from cheap manifest row counts. Under good coverage this
reduces to a selectivity ratio independent of |E|, preserving the flat-in-|E|
indexed win for selective traversals while routing dense / deep / high-fanout
or degraded-and-expensive traversals to CSR.

execute_expand decides cardinality-first and only opens the edge dataset to
confirm coverage when it leans indexed (no open on a clearly-CSR traversal).
The two env knobs become hard ceilings layered on the model; the
OMNIGRAPH_TRAVERSAL_MODE override still forces a path; the chosen mode is
traced. Results are unchanged across modes — only the path differs.

Adds inline crossover unit tests and extends the traversal_indexed both_modes
harness with an auto pass asserting the chooser is result-preserving across
every traversal shape. Documents the new flag semantics in
docs/user/{constants,query-language}.md.
2026-06-09 09:34:03 +02:00
..
dev fix: optimize publishes compaction; recovery roll-back converges manifest (#141) 2026-06-08 02:50:12 +03:00
releases feat(engine): sweep & remove legacy __run__ branch guard (MR-770) (#132) 2026-06-07 18:33:14 +03:00
rfcs governance: external contribution model (issues/discussions/RFCs/PRs) (#143) 2026-06-06 23:58:08 +03:00
user feat(engine): cost-based Expand dispatch chooser (C5) 2026-06-09 09:34:03 +02:00