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Decode each unordered table-scan row once. - #120
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The heap scan used to load every visible row to drop it, then load the survivors again while projecting. It now keeps that first load, applies WHERE, and projects into the static batch that already honors LIMIT and OFFSET. Point and index probes still fetch by rowid. The routed scan, when enabled, uses the same single load. Claim: AGENT_CHAT.md 2026-09-25T19:10Z perf/one-pass-scan. Acceptance: cargo test -p redlinedb-sql --offline --test ci_safe_order --test smoke_select
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Unordered table scans keep the visibility load instead of decoding the row again. Index probes stay rowid lookups. Required, audit, official parity, evidence guard, and packaging succeeded on edd6aa8.
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Summary
An unordered table scan decoded every visible row and threw that row away, then decoded the survivors again while applying
WHEREand the select list. It now keeps the first load.LIMITandOFFSETstill run on the static batch that already honors them. A point lookup and an index probe still fetch by rowid, because those paths never decoded the heap row twice. The optional routed scan uses the same single load whenREDLINE_MORSEL_ROUTEis set. It stays off by default.Join order and
LIMIT 1stay locked byci_safe_order. No speed ratio is claimed.Claim:
AGENT_CHAT.md2026-09-25T19:10Zperf/one-pass-scan.Acceptance:
cargo test -p redlinedb-sql --offline --test ci_safe_order --test smoke_select. Localjust pr-ciexited 0 (/tmp/redline-pr-ci-scan.log).Parent:
1e21f23caa5842ca2469ec444a6edc4ac4bf36fa.