From 68dca986ee7ff7d729a15565e2e07127d5b5d1a4 Mon Sep 17 00:00:00 2001 From: eunhhu Date: Wed, 30 Sep 2026 13:52:30 +0100 Subject: Say that prefetching items did not pay, and why (109) Fetching a found item's cells, a leaf's keys and each level's keys ahead made finding and reading items 20% faster on 100,000 items in a micro benchmark, but TPC-C's clean pairs moved 1% at most and finding alone got 48% slower, so it is not in. The owner's finding samples were the descent, not the fields: a write right after a read copies the leaf whole anyway, and what costs is walking structures larger than the caches at random. --- .../024-finding-items/2026-09-30-tpcc-before-5-linux-aarch64.jsonl | 3 +++ 1 file changed, 3 insertions(+) create mode 100644 research/experiments/024-finding-items/2026-09-30-tpcc-before-5-linux-aarch64.jsonl (limited to 'research/experiments/024-finding-items/2026-09-30-tpcc-before-5-linux-aarch64.jsonl') diff --git a/research/experiments/024-finding-items/2026-09-30-tpcc-before-5-linux-aarch64.jsonl b/research/experiments/024-finding-items/2026-09-30-tpcc-before-5-linux-aarch64.jsonl new file mode 100644 index 0000000..6c90e25 --- /dev/null +++ b/research/experiments/024-finding-items/2026-09-30-tpcc-before-5-linux-aarch64.jsonl @@ -0,0 +1,3 @@ +{"step": "load", "directory": "/dev/shm", "warehouses": 1, "rows": 568758, "generate_s": 0.56, "pure_load_s": 0.7, "sqlite_load_s": 1.64, "sqlite_page_size": 4096, "pure_resident_mib": 38.9, "sqlite_file_mib": 13.8} +{"step": "run", "system": "pure", "warehouses": 1, "terminals": 64, "transactions_per_second": 37963, "new_orders_per_minute": 1015262, "undone_new_orders": 3254, "errors": 0, "new_order": {"done": 341679, "failed": 0, "p50_us": 1536, "p99_us": 4608}, "payment": {"done": 326457, "failed": 0, "p50_us": 1536, "p99_us": 4608}, "order_status": {"done": 30460, "failed": 0, "p50_us": 288, "p99_us": 2304}, "delivery": {"done": 30463, "failed": 0, "p50_us": 1536, "p99_us": 4864}, "stock_level": {"done": 30208, "failed": 0, "p50_us": 320, "p99_us": 2304}, "server_threads": "3", "cpu_us_per_transaction": 45.7, "core_shares": {"pure-owner": 0.82, "pure-checkpoint": 0.01}, "resident_mib": 407.7, "written_bytes_per_transaction": 0.0, "device_bytes_per_transaction": null, "consistency_failures": []} +{"step": "end", "pure_resident_mib": 407.7, "pure_state_mib": 205.0, "pure_store_mib": 214.7, "sqlite_files_mib": 13.8, "grouped_sqlite_files_mib": 0.0, "pure_counts": {"bursts": 24124, "burst_events": 695431, "checkpoints": 33}} -- cgit v1.2.3