exp 184: writer residual re-split (post-159/180) — measurement

[danReynolds]

Measurement experiment (no runtime code → auto-merge eligible).

Re-ran exp 147's writer_sqlite_wall_audit on main after pipelining (exp 159) + group commit (exp 180) to re-rank the next writer target.

workload (sequential)	SQLite	invalidation	residual	exp 147
A11c baseline	38%	0%	62%	—
A11c disjoint	24%	22%	55%	~55%
A11c overlap	14%	16%	70%	72%
keyed PK	24%	14%	62%	63%

Essentially unchanged — expected: the audit issues writes sequentially (audit_workloads.dart:167) and exp 180 coalesces only concurrent bursts, so the sequential path it measures is unmoved (exp 180's win is on the concurrent release lane, validated separately).

Conclusion — retire writer-residual micro-opts:

• Residual (55–70%) = the per-write isolate round-trip = SDK-gated floor (lever: shared-memory transport).
• Invalidation/re-query precision (14–22%) = owned by in-flight exp 160 (Exp 160: incremental view maintenance — the v2 stream engine #155); traversal already at floor (exp 121).
• Dirty harvest (~4–6%, exp 182) = small; gating it regresses with-streams.
• SQLite (14–38%) = sqlite3mc config, mined.

Next reactive-engine win = exp 160; next sequential-write reduction = shared-memory transport.

🤖 Generated with Claude Code