Overview planner charges for the sections it will actually run

src/core/query/overview.js

@@ -222,16 +222,37 @@ const SECTION_COST_VS_PROBE = 1.9
  * Without a probe timing there is nothing to infer from, so the caller
  * falls back to the row cap alone (`Infinity` here defers to it).
  *
- * @param {{ budgetMs?: number, probeMs?: number, totalRows: number }} args
+ * `sections` is what is about to run, not the list of sections that exist.
+ * `collectOverview` executes only the sections it was asked for, so
+ * charging a two-section caller for four halves the window it gets in
+ * exchange for work nobody will do - and the narrowing is invisible to it,
+ * since a window bound by time reports no reason. LLP 0135 #window puts the
+ * divisor as `perRowMs x 1.9 x sections`, which is the count planned.
+ *
+ * An empty section list divides by zero and yields `Infinity`, which is the
+ * honest answer: no sections means no section cost, and the row cap decides
+ * a window nothing will scan.
+ *
+ * @ref LLP 0135#window [implements]: the cost model's section term is the sections being planned for
+ * @param {{
+ *   budgetMs?: number,
+ *   probeMs?: number,
+ *   totalRows: number,
+ *   sections?: readonly ('models'|'daily'|'repos'|'tools')[],
+ * }} args
  * @returns {number}
  */
-function rowsAffordable({ budgetMs = OVERVIEW_TIME_BUDGET_MS, probeMs, totalRows }) {
+function rowsAffordable({
+  budgetMs = OVERVIEW_TIME_BUDGET_MS,
+  probeMs,
+  totalRows,
+  sections = OVERVIEW_SECTIONS,
+}) {
   if (probeMs === undefined || totalRows <= 0) return Infinity
   // A probe too fast to time is not evidence of infinite speed; floor it at
   // 1ms so the estimate stays finite and the row cap keeps its say.
   const perRowMs = Math.max(probeMs, 1) / totalRows
-  const sectionCount = OVERVIEW_SECTIONS.length
-  return Math.floor(budgetMs / (perRowMs * SECTION_COST_VS_PROBE * sectionCount))
+  return Math.floor(budgetMs / (perRowMs * SECTION_COST_VS_PROBE * sections.length))
 }
 
 /** Rows shown per section before the remainder is folded into a count line. */
@@ -367,9 +388,11 @@ export function overviewRunnerFromCtx(ctx, onNotice, opts = {}) {
  *   days?: number,
  *   budgetMs?: number,
  *   probeMs?: number,
+ *   sections?: readonly ('models'|'daily'|'repos'|'tools')[],
  * }} [opts] `days` pins an explicit window (the user asked for it) and
  *   skips both caps; `probeMs` is how long the probe took over every row,
- *   which calibrates the time cap to this machine
+ *   which calibrates the time cap to this machine; `sections` is the work
+ *   the time cap is being asked to pay for, defaulting to all four
  * @returns {OverviewWindow | null} null when nothing has been recorded
  * @ref LLP 0135#window [implements]: the affordable-window plan, measured on the machine it runs on
  */
@@ -392,6 +415,7 @@ export function chooseOverviewWindow(probeRows, opts = {}) {
   const timeCap = rowsAffordable({
     budgetMs: sectionBudgetMs,
     ...(opts.probeMs !== undefined ? { probeMs: opts.probeMs } : {}),
+    ...(opts.sections !== undefined ? { sections: opts.sections } : {}),
     totalRows,
   })
   const cap = Math.min(rowCap, timeCap)
@@ -444,9 +468,18 @@ export function hasRenderableOverview(rows) {
 }
 
 /**
- * Which of the requested sections have landed. Lets a caller that stopped
- * early say what is missing rather than presenting a short block as whole.
+ * Which of the requested sections have not landed. Lets a caller that
+ * stopped early say what is missing rather than presenting a short block as
+ * whole.
+ *
+ * Requested, not existing: the wizard prints this list as "the repos and
+ * tools sections did not finish", and a section nobody asked for did not
+ * fail to finish - it was never started. Naming it would be the same false
+ * claim as calling an unfinished section empty, in the other direction.
+ * `collectOverview` stamps the plan on the result, so a subset run carries
+ * what it meant to do; a result assembled by hand falls back to all four.
  *
+ * @ref LLP 0135#overrun [implements]: unfinished sections are named as unfinished, which only the requested ones can be
  * @param {OverviewRows} rows
  * @returns {('models'|'daily'|'repos'|'tools')[]}
  */
@@ -458,7 +491,7 @@ export function missingSections(rows) {
     repos: rows.repoRows,
     tools: rows.toolRows,
   }
-  return OVERVIEW_SECTIONS.filter((s) => byName[s].length === 0)
+  return (rows.sections ?? OVERVIEW_SECTIONS).filter((s) => byName[s].length === 0)
 }
 
 /**
@@ -492,6 +525,10 @@ export async function collectOverview(runner, opts = {}) {
   const sections = opts.sections ?? OVERVIEW_SECTIONS
   const clock = opts.clock ?? Date.now
   const out = opts.into ?? emptyOverview()
+  // Recorded on the result, before any await, because after an abandoned
+  // run the result object is all the caller still holds - and `missing`
+  // means "asked for and did not land", which needs the plan to read.
+  out.sections = sections
 
   // Timing the probe is what makes the plan an observation of this machine
   // rather than an assumption about it: the probe reads every row, so its
@@ -502,6 +539,7 @@ export async function collectOverview(runner, opts = {}) {
   const probeMs = Math.max(0, clock() - probeStart)
   const window = chooseOverviewWindow(probe.rows, {
     probeMs,
+    sections,
     ...(opts.targetRows !== undefined ? { targetRows: opts.targetRows } : {}),
     ...(opts.budgetMs !== undefined ? { budgetMs: opts.budgetMs } : {}),
     ...(opts.days !== undefined ? { days: opts.days } : {}),

src/core/query/types.d.ts

@@ -156,6 +156,14 @@ export interface OverviewRows {
   toolRows: Record<string, unknown>[]
   window?: OverviewWindow
   sql?: { models: string; daily: string; repos: string; tools: string }
+  /**
+   * The sections this run set out to fill, stamped by `collectOverview`
+   * before it runs anything. It is what tells an empty section that was
+   * never requested from one that did not finish, which is the difference
+   * between the two sentences LLP 0135 #overrun insists on. Absent on a
+   * result nobody collected into, where all four are assumed.
+   */
+  sections?: readonly ('models' | 'daily' | 'repos' | 'tools')[]
 }
 
 /**

test/core/query-overview.test.js

@@ -15,7 +15,9 @@ import {
   chooseOverviewWindow,
   collectOverview,
   describeWindow,
+  emptyOverview,
   formatCount,
+  missingSections,
   overviewRunnerFromCtx,
   renderDailyActivity,
   renderOverview,
@@ -524,6 +526,35 @@ test('chooseOverviewWindow: with no probe timing, the row cap decides alone', ()
   assert.equal(win?.boundBy, 'rows')
 })
 
+/** 20 days x 10k rows, newest first, on dates that sort as strings. */
+function twentyDayProbe() {
+  return Array.from({ length: 20 }, (_, i) => ({
+    date: `2026-07-${String(20 - i).padStart(2, '0')}`,
+    n: 10_000,
+  }))
+}
+
+test('chooseOverviewWindow: the plan charges for the sections it will run, not all four', () => {
+  // LLP 0135 #window states the estimate as `remaining / (perRowMs x 1.9 x
+  // sections)`, and `collectOverview` runs only the sections it was asked
+  // for. Half the work is half the cost, so a two-section caller can afford
+  // roughly twice the rows on the same machine and the same budget.
+  const probe = twentyDayProbe()
+  const opts = { targetRows: 1e9, budgetMs: 5000, probeMs: 2000 }
+
+  const four = chooseOverviewWindow(probe, opts)
+  const two = chooseOverviewWindow(probe, { ...opts, sections: ['models', 'daily'] })
+
+  assert.ok(four && two)
+  assert.equal(four.boundBy, 'time')
+  assert.equal(two.boundBy, 'time')
+  // 3000ms left after the probe, at 0.01ms/row: 39,473 rows for four
+  // sections, 78,947 for two - three days against seven.
+  assert.equal(four.days, 3)
+  assert.equal(two.days, 7)
+  assert.ok(two.rows > four.rows * 2, `${two.rows} should be over twice ${four.rows}`)
+})
+
 test('chooseOverviewWindow: an explicit --days request outranks both caps', () => {
   const probe = Array.from({ length: 10 }, (_, i) => ({ date: `2026-07-${20 - i}`, n: 1_000_000 }))
   // Row cap tiny, machine measured as glacial: the user asked anyway.
@@ -603,6 +634,56 @@ test('collectOverview: probes first, then runs only the requested sections', asy
   assert.deepEqual(rows.toolRows, [])
 })
 
+/** A runner that answers the probe with `probe` and every section one row. */
+function answeringRunner(probe) {
+  return {
+    hasDataset: () => true,
+    /** @param {string} sql */
+    async run(sql) {
+      return { columns: [], rows: sql === OVERVIEW_PROBE_SQL ? probe : [{ n: 1 }] }
+    },
+  }
+}
+
+/** A clock whose second reading is `ms` later, so the probe times exactly. */
+function clockSpending(ms) {
+  let calls = 0
+  return () => (calls++ === 0 ? 0 : ms)
+}
+
+test('collectOverview: the window is planned for the sections actually requested', async () => {
+  // The same machine, the same budget, the same cache - only the section
+  // list differs, and the subset caller is not charged for work it will
+  // never do.
+  const probe = twentyDayProbe()
+  const four = await collectOverview(answeringRunner(probe), {
+    targetRows: 1e9,
+    clock: clockSpending(2000),
+  })
+  const two = await collectOverview(answeringRunner(probe), {
+    sections: ['models', 'daily'],
+    targetRows: 1e9,
+    clock: clockSpending(2000),
+  })
+  assert.equal(four.window?.days, 3)
+  assert.equal(two.window?.days, 7)
+})
+
+test('missingSections: a section nobody asked for is not reported as unfinished', async () => {
+  // "The repos section did not finish" and "you did not ask for repos" are
+  // different claims, and the wizard prints the first one verbatim
+  // (LLP 0135 #overrun). A subset run has nothing missing.
+  const probe = [{ date: '2026-07-24', n: 10 }]
+  const two = await collectOverview(answeringRunner(probe), { sections: ['models', 'daily'] })
+  assert.deepEqual(missingSections(two), [])
+
+  // And a section that was asked for and did not land is still named.
+  const { runner } = probingRunner(probe)
+  const none = await collectOverview(runner, { sections: ['models', 'repos'] })
+  assert.deepEqual(missingSections(none), ['models', 'repos'])
+  assert.deepEqual(missingSections(emptyOverview()), ['models', 'daily', 'repos', 'tools'])
+})
+
 test('collectOverview: runs all four sections by default, in display order', async () => {
   const { seen, runner } = probingRunner([{ date: '2026-07-24', n: 10 }])
   const rows = await collectOverview(runner)