{"slowdowns":[{"arch":"arm","confidence":{"confirmationThreshold":0.23273021725299936,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Estimated slowdown: 27.2%. Minimum meaningful slowdown: 23.3% adaptive threshold; see C3. Conservative low estimate: 23.6%, computed as the lower bound of the old-vs-new interval from repeated measurements, still above the minimum.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"3.000"},{"label":"Estimate","reference":"ref: threshold 1.233","value":"1.272"},{"label":"Robust interval","value":"1.236 to 1.311"},{"label":"Raw samples","value":"7 old / 7 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.2842447955759746,1.2796346550450501,1.2709997050568893,1.272317693203729,1.2693257575391594],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.57934018,0.5824720999999999,0.5849881,0.58694292,0.590132324],"oldQuantiles":[0.451113512,0.45518625,0.46025825,0.461317895,0.464917946],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is larger than this test-specific threshold from recent master history of 23.3% (2.0% base, 11.6% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"11.6%"},{"label":"Adaptive threshold","reference":"ref: observed 27.0%","value":"23.3%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 05:07:10 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed 27.0%","value":"11.6%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"2.320"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"Historical series looks unimodal, so no fleet penalty was applied.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"No"},{"label":"MValue","value":"4.522"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"0.000"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"Nearby master runs look normal around this run.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"116"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"1.433"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"2.340"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"0.192"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"2.774"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"-0.871"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Local Context"},{"code":"PR","effectQuantiles":null,"interpretation":"Not enough same-PR history: at least six earlier distinct commits are required.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Window","reference":"current commit and later observations excluded","value":"14 days before run"},{"label":"Earlier commits","reference":"one sample per distinct commit; repeated measurements do not add samples","value":"1 / 6 required"},{"label":"Slowdowns / speedups","reference":"each must clear the 15% and statistical thresholds","value":"0 / 0"},{"label":"Comparable slowdowns","reference":"at least as large as the current change","value":"0 / 2 required"},{"label":"Comparable speedups","reference":"reciprocal ratios make speedups and slowdowns comparable","value":"0 / 2 required"},{"label":"Current slowdown","value":"27.1%"},{"label":"Repeated-shift threshold","reference":"second-largest shift in each direction; the smaller sets the limit","value":"Unavailable"},{"label":"Cap applied","reference":"lower confidence tiers are never raised","value":"No"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Same-PR History"}],"reason":"Confidence capped at likely regression: this query/metric/architecture ranks #6 in Flaky lately (score 922, 14-day window; top-150 policy). Repeated PR measurements show a slowdown larger than the minimum we require for this metric, with enough margin to be confident this is not just measurement noise. Quantiles confirm a broad slowdown across the distribution.","tier":"likely_regression"},"diffPercent":0.27000001072883606,"direction":"slowdown","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":84,"metric":"client_time","negativeFlags":780,"positiveFlags":430,"prFlags":838,"queryIndex":6,"rank":6,"score":922,"test":"optimize_time_filter_with_preimage","windowDays":14},"metric":"client_time","newValue":0.5849000215530396,"oldValue":0.4602000117301941,"queryDisplayName":"\n        SELECT count()\n        FROM date_preimage_perf\n        WHERE toStartOfMonth(d) = toDate('2026-03-01')\n        SETTINGS optimize_time_filter_with_preimage = 0\n    ","queryIndex":6,"reportLinks":[],"severity":"regression","statThreshold":0.27,"test":"optimize_time_filter_with_preimage"},{"arch":"arm","confidence":{"confirmationThreshold":0.1558695221870521,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Repeated PR measurements do not consistently stay above the minimum slowdown required for this metric.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"0.000"},{"label":"Estimate","reference":"ref: threshold 1.156","value":"1.187"},{"label":"Robust interval","value":"1.095 to 1.333"},{"label":"Raw samples","value":"7 old / 7 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.2259493839272608,1.1940358058043625,1.1869556142520508,1.156522283359246,1.1818269007028386],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.055618,0.056175113,0.057663918,0.0583376885,0.0599023338],"oldQuantiles":[0.045367289000000005,0.047046422500000004,0.04858136,0.0504423385,0.050686216199999995],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is larger than this test-specific threshold from recent master history of 15.6% (2.0% base, 7.8% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"7.8%"},{"label":"Adaptive threshold","reference":"ref: observed 18.6%","value":"15.6%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 05:15:36 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed 18.6%","value":"7.8%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"2.387"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"Historical series looks unimodal, so no fleet penalty was applied.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"No"},{"label":"MValue","value":"2.776"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"0.000"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"Nearby master runs look normal around this run.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"123"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"0.126"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"2.858"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"1.848"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"2.162"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"-0.078"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Local Context"},{"code":"PR","effectQuantiles":null,"interpretation":"Not enough same-PR history: at least six earlier distinct commits are required.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Window","reference":"current commit and later observations excluded","value":"14 days before run"},{"label":"Earlier commits","reference":"one sample per distinct commit; repeated measurements do not add samples","value":"1 / 6 required"},{"label":"Slowdowns / speedups","reference":"each must clear the 15% and statistical thresholds","value":"0 / 0"},{"label":"Comparable slowdowns","reference":"at least as large as the current change","value":"0 / 2 required"},{"label":"Comparable speedups","reference":"reciprocal ratios make speedups and slowdowns comparable","value":"0 / 2 required"},{"label":"Current slowdown","value":"18.8%"},{"label":"Repeated-shift threshold","reference":"second-largest shift in each direction; the smaller sets the limit","value":"Unavailable"},{"label":"Cap applied","reference":"lower confidence tiers are never raised","value":"No"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Same-PR History"}],"reason":"The repeated PR measurements are not consistently larger than the minimum slowdown required for this metric. Master runs show a slowdown this large often: 7.1% of the last 492 master runs (14 days) of this query showed a slowdown of at least 14.9%.","tier":"noise"},"diffPercent":0.1860000044107437,"direction":"slowdown","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":68,"metric":"client_time","negativeFlags":431,"positiveFlags":203,"prFlags":468,"queryIndex":0,"rank":13,"score":536,"test":"vectorize_aggregation_combinators","windowDays":14},"metric":"client_time","newValue":0.0575999990105629,"oldValue":0.048500001430511475,"queryDisplayName":"SELECT countMerge(v) FROM (SELECT countState() v FROM zeros(1000000000)) FORMAT Null","queryIndex":0,"reportLinks":[],"severity":"regression","statThreshold":0.186,"test":"vectorize_aggregation_combinators"},{"arch":"arm","confidence":{"confirmationThreshold":0.07174875606837043,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Estimated slowdown: 16.0%. Minimum meaningful slowdown: 7.2% adaptive threshold; see C3. Conservative low estimate: 15.0%, computed as the lower bound of the old-vs-new interval from repeated measurements, still above the minimum.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"3.000"},{"label":"Estimate","reference":"ref: threshold 1.072","value":"1.160"},{"label":"Robust interval","value":"1.150 to 1.168"},{"label":"Raw samples","value":"30 old / 30 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.1620650263961705,1.1600564409482532,1.1603965282361357,1.1602520635989402,1.1400642635452471],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.0124008896,0.01244080025,0.0125017165,0.012565374374999999,0.0125966071],"oldQuantiles":[0.01067142485,0.010724306000000001,0.010773659000000001,0.010829865999999999,0.0110490325],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is larger than this test-specific threshold from recent master history of 7.2% (2.0% base, 3.6% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"3.6%"},{"label":"Adaptive threshold","reference":"ref: observed 16.0%","value":"7.2%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 04:53:01 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed 16.0%","value":"3.6%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"4.460"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"This architecture's published history is multimodal; the current comparison does not establish a one-architecture-only slowdown.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"Yes"},{"label":"MValue","value":"2.035"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"1.012"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"Nearby master runs show an unusual baseline-vs-PR contrast around this run.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"84"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"2.113"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"17.414"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"1.637"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"5.297"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"-0.528"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Local Context"},{"code":"PR","effectQuantiles":null,"interpretation":"Not enough same-PR history: at least six earlier distinct commits are required.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Window","reference":"current commit and later observations excluded","value":"14 days before run"},{"label":"Earlier commits","reference":"one sample per distinct commit; repeated measurements do not add samples","value":"0 / 6 required"},{"label":"Slowdowns / speedups","reference":"each must clear the 15% and statistical thresholds","value":"0 / 0"},{"label":"Comparable slowdowns","reference":"at least as large as the current change","value":"0 / 2 required"},{"label":"Comparable speedups","reference":"reciprocal ratios make speedups and slowdowns comparable","value":"0 / 2 required"},{"label":"Current slowdown","value":"16.8%"},{"label":"Repeated-shift threshold","reference":"second-largest shift in each direction; the smaller sets the limit","value":"Unavailable"},{"label":"Cap applied","reference":"lower confidence tiers are never raised","value":"No"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Same-PR History"}],"reason":"Repeated PR measurements show a slowdown larger than the minimum we require for this metric, with enough margin to be confident this is not just measurement noise. Quantiles confirm a broad slowdown across the distribution.","tier":"confirmed_regression"},"diffPercent":0.1599999964237213,"direction":"slowdown","metric":"client_time","newValue":0.012500000186264515,"oldValue":0.010700000450015068,"queryDisplayName":"SELECT max(small_i128) FROM minmax_wide","queryIndex":4,"reportLinks":[],"severity":"regression","statThreshold":0.15,"test":"min_max_wide_integers"}],"speedups":[{"arch":"arm","confidence":{"confirmationThreshold":0.23529418670211857,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Estimated slowdown: 32.6%. Minimum meaningful slowdown: 23.5% adaptive threshold; see C3. Conservative low estimate: 25.2%, computed as the lower bound of the old-vs-new interval from repeated measurements, still above the minimum.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"3.000"},{"label":"Estimate","reference":"ref: threshold 1.235","value":"1.326"},{"label":"Robust interval","value":"1.252 to 1.397"},{"label":"Raw samples","value":"30 old / 30 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.256121793123329,1.264674312691842,1.3341007364570674,1.3799722567589998,1.4089701736264955],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.00536415577,0.005481064325,0.0058716535,0.0061497094,0.0064367532900000005],"oldQuantiles":[0.00427041056,0.004333973,0.004401207,0.004456400750000001,0.0045684099],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is larger than this test-specific threshold from recent master history of 23.5% (2.0% base, 11.8% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"11.8%"},{"label":"Adaptive threshold","reference":"ref: observed -25.4%","value":"23.5%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 05:13:42 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed -25.4%","value":"11.8%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"2.159"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"This architecture's published history is multimodal; the current comparison does not establish a one-architecture-only slowdown.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"Yes"},{"label":"MValue","value":"4.498"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"1.108"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"The baseline side looks much more unusual than the PR side compared with nearby master runs. This may be a baseline artifact.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"119"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"2.548"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"3.520"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"4.817"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"0.744"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"+0.733"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Local Context"}],"reason":"Repeated PR measurements show a slowdown larger than the minimum we require for this metric, with enough margin to be confident this is not just measurement noise. Quantiles confirm a broad slowdown across the distribution. The baseline side looks unusual compared with nearby master runs, so the apparent slowdown may be caused by the baseline rather than the PR.","tier":"likely_regression"},"diffPercent":-0.2540000081062317,"direction":"speedup","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":108,"metric":"client_time","negativeFlags":619,"positiveFlags":386,"prFlags":707,"queryIndex":2,"rank":10,"score":815,"test":"rand","windowDays":14},"metric":"client_time","newValue":0.004399999976158142,"oldValue":0.005799999926239252,"queryDisplayName":"SELECT count() FROM (SELECT randUniform(0, 1) FROM zeros(100000000)) ","queryIndex":2,"reportLinks":[],"severity":"improvement","statThreshold":0.188,"test":"rand"},{"arch":"arm","confidence":{"confirmationThreshold":0.2913417504167264,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Repeated PR measurements do not consistently stay above the minimum slowdown required for this metric.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"0.000"},{"label":"Estimate","reference":"ref: threshold 1.291","value":"1.312"},{"label":"Robust interval","value":"1.254 to 1.432"},{"label":"Raw samples","value":"7 old / 7 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.2874934758169772,1.2965040870108293,1.3122692555069366,1.3346516781292348,1.364404168495884],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.0404708392,0.041075707,0.04168296,0.042560339,0.043716907799999996],"oldQuantiles":[0.031433820800000005,0.0316818955,0.03176403,0.031888724,0.0320410248],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is below this test-specific threshold from recent master history of 29.1% (2.0% base, 14.6% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"14.6%"},{"label":"Adaptive threshold","reference":"ref: observed -23.8%","value":"29.1%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 05:13:42 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed -23.8%","value":"14.6%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"1.634"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"Historical series looks unimodal, so no fleet penalty was applied.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"No"},{"label":"MValue","value":"3.802"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"0.000"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"The baseline side looks much more unusual than the PR side compared with nearby master runs. This may be a baseline artifact.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"113"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"1.854"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"2.568"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"3.692"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"0.791"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"+0.647"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Local Context"}],"reason":"The change is smaller than the threshold suggested by recent master history. The baseline side looks unusual compared with nearby master runs, so the apparent slowdown may be caused by the baseline rather than the PR. Master runs show a slowdown this large often: 9.3% of the last 442 master runs (14 days) of this query showed a slowdown of at least 19.0%.","tier":"noise"},"diffPercent":-0.23800000548362732,"direction":"speedup","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":151,"metric":"client_time","negativeFlags":814,"positiveFlags":564,"prFlags":880,"queryIndex":1,"rank":3,"score":1031,"test":"rand","windowDays":14},"metric":"client_time","newValue":0.031700000166893005,"oldValue":0.041600000113248825,"queryDisplayName":"SELECT count() FROM (SELECT rand64()         FROM zeros(1000000000)) ","queryIndex":1,"reportLinks":[],"severity":"improvement","statThreshold":0.237,"test":"rand"},{"arch":"arm","confidence":{"confirmationThreshold":0.20338995892985826,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Estimated slowdown: 28.6%. Minimum meaningful slowdown: 20.3% adaptive threshold; see C3. Conservative low estimate: 23.9%, computed as the lower bound of the old-vs-new interval from repeated measurements, still above the minimum.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"3.000"},{"label":"Estimate","reference":"ref: threshold 1.203","value":"1.286"},{"label":"Robust interval","value":"1.239 to 1.349"},{"label":"Raw samples","value":"30 old / 30 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.2452134286810121,1.26498660698723,1.2946123292970424,1.3198220807119785,1.3604397072066923],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.00528450013,0.0054122211000000005,0.00559723375,0.005818486225000001,0.00608987806],"oldQuantiles":[0.0042438509,0.00427848095,0.0043234825,0.004408538325,0.004476404230000001],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is larger than this test-specific threshold from recent master history of 20.3% (2.0% base, 10.2% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"10.2%"},{"label":"Adaptive threshold","reference":"ref: observed -22.9%","value":"20.3%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 05:13:42 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed -22.9%","value":"10.2%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"2.252"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"This architecture's published history is multimodal; the current comparison does not establish a one-architecture-only slowdown.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"Yes"},{"label":"MValue","value":"4.305"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"1.063"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"The baseline side looks much more unusual than the PR side compared with nearby master runs. This may be a baseline artifact.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"117"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"2.802"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"3.402"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"4.756"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"1.076"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"+0.631"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Local Context"}],"reason":"Repeated PR measurements show a slowdown larger than the minimum we require for this metric, with enough margin to be confident this is not just measurement noise. Quantiles confirm a broad slowdown across the distribution. The baseline side looks unusual compared with nearby master runs, so the apparent slowdown may be caused by the baseline rather than the PR. Master runs show a slowdown this large often: 7.0% of the last 457 master runs (14 days) of this query showed a slowdown of at least 18.3%.","tier":"suspect"},"diffPercent":-0.2290000021457672,"direction":"speedup","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":124,"metric":"client_time","negativeFlags":639,"positiveFlags":412,"prFlags":722,"queryIndex":3,"rank":8,"score":846,"test":"rand","windowDays":14},"metric":"client_time","newValue":0.00430000014603138,"oldValue":0.00559999980032444,"queryDisplayName":"SELECT count() FROM (SELECT generateUUIDv4() FROM zeros( 100000000)) ","queryIndex":3,"reportLinks":[],"severity":"improvement","statThreshold":0.18,"test":"rand"},{"arch":"arm","confidence":{"confirmationThreshold":0.15151510661668005,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Estimated slowdown: 30.5%. Minimum meaningful slowdown: 15.2% adaptive threshold; see C3. Conservative low estimate: 25.4%, computed as the lower bound of the old-vs-new interval from repeated measurements, still above the minimum.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"3.000"},{"label":"Estimate","reference":"ref: threshold 1.152","value":"1.305"},{"label":"Robust interval","value":"1.254 to 1.350"},{"label":"Raw samples","value":"30 old / 30 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.326145353999194,1.322810406434797,1.3000847643369882,1.2836867635122666,1.2612793927884831],"interpretation":"Quantile shift is broad: most of the distribution moved in the slowdown direction.","newQuantiles":[0.00781793592,0.00791484125,0.008045435,0.0081568955,0.008301377450000001],"oldQuantiles":[0.00589523305,0.005983352725,0.00618839265,0.006354272500000001,0.006581711790000001],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"supports"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"broad_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is larger than this test-specific threshold from recent master history of 15.2% (2.0% base, 7.6% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"7.6%"},{"label":"Adaptive threshold","reference":"ref: observed -22.8%","value":"15.2%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 04:03:07 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed -22.8%","value":"7.6%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"3.010"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"This architecture's published history is multimodal; the current comparison does not establish a one-architecture-only slowdown.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"Yes"},{"label":"MValue","value":"4.143"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"64.164"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"The baseline-vs-PR contrast remains unusual compared with nearby master runs.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"18"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"2.950"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"6.594"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"1.172"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"3.093"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"-0.450"},{"label":"Conditional contrast","reference":"contrast after accounting for local level","value":"7.675"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Local Context"}],"reason":"Repeated PR measurements show a slowdown larger than the minimum we require for this metric, with enough margin to be confident this is not just measurement noise. Quantiles confirm a broad slowdown across the distribution.","tier":"confirmed_regression"},"diffPercent":-0.2280000001192093,"direction":"speedup","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":6,"metric":"client_time","negativeFlags":43,"positiveFlags":40,"prFlags":73,"queryIndex":2,"rank":89,"score":79,"test":"formats_columns_nullable","windowDays":14},"metric":"client_time","newValue":0.006200000178068876,"oldValue":0.00800000037997961,"queryDisplayName":"SELECT * FROM table_JSONEachRow_with_nullable_columns LIMIT 1000 FORMAT Null","queryIndex":2,"reportLinks":[],"severity":"improvement","statThreshold":0.199,"test":"formats_columns_nullable"},{"arch":"arm","confidence":{"confirmationThreshold":0.29441946060407864,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Repeated PR measurements do not consistently stay above the minimum slowdown required for this metric.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"0.000"},{"label":"Estimate","reference":"ref: threshold 1.294","value":"1.281"},{"label":"Robust interval","value":"1.186 to 1.379"},{"label":"Raw samples","value":"7 old / 7 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.2191162567960552,1.2494924628618045,1.2814929987321069,1.3096219089120429,1.3331549045771467],"interpretation":"Upper-tail quantiles moved most, which suggests instability more than a broad shift.","newQuantiles":[0.038686084999999995,0.039767265499999996,0.04094553,0.041984797500000004,0.042879725],"oldQuantiles":[0.031732892400000004,0.031826735,0.031951427,0.0320587165,0.032164098],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"neutral"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"upper_tail_shift"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is below this test-specific threshold from recent master history of 29.4% (2.0% base, 14.7% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"14.7%"},{"label":"Adaptive threshold","reference":"ref: observed -22.0%","value":"29.4%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 05:13:42 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed -22.0%","value":"14.7%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"1.494"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"Historical series looks unimodal, so no fleet penalty was applied.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"No"},{"label":"MValue","value":"4.415"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"0.000"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"The baseline side looks much more unusual than the PR side compared with nearby master runs. This may be a baseline artifact.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"117"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"2.078"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"2.256"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"3.534"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"0.850"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"+0.612"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Local Context"}],"reason":"The change is smaller than the threshold suggested by recent master history. The baseline side looks unusual compared with nearby master runs, so the apparent slowdown may be caused by the baseline rather than the PR. Master runs show a slowdown this large often: 9.6% of the last 447 master runs (14 days) of this query showed a slowdown of at least 17.6%.","tier":"noise"},"diffPercent":-0.2199999988079071,"direction":"speedup","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":146,"metric":"client_time","negativeFlags":803,"positiveFlags":554,"prFlags":868,"queryIndex":0,"rank":4,"score":1014,"test":"rand","windowDays":14},"metric":"client_time","newValue":0.03189999982714653,"oldValue":0.04089999943971634,"queryDisplayName":"SELECT count() FROM (SELECT rand()           FROM zeros(1000000000)) ","queryIndex":0,"reportLinks":[],"severity":"improvement","statThreshold":0.219,"test":"rand"},{"arch":"arm","confidence":{"confirmationThreshold":0.2736882586449404,"modules":[{"code":"C1","effectQuantiles":null,"interpretation":"Repeated PR measurements do not consistently stay above the minimum slowdown required for this metric.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Evidence score","reference":"ref: stronger evidence grows roughly 1, 2, 3","value":"0.000"},{"label":"Estimate","reference":"ref: threshold 1.274","value":"1.181"},{"label":"Robust interval","value":"1.157 to 1.203"},{"label":"Raw samples","value":"7 old / 7 new"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"Raw Sample Evidence"},{"code":"C2","effectQuantiles":[1.1798743332740076,1.1791313967440074,1.180035103415743,1.1830835509394773,1.1807053010742232],"interpretation":"Quantiles are mixed, so C2 stays explanatory-only.","newQuantiles":[0.6243268599999999,0.62628747,0.6292572,0.63492442,0.63598138],"oldQuantiles":[0.529146912,0.5311430699999999,0.53325295,0.53666913,0.538645316],"probabilities":[0.1,0.25,0.5,0.75,0.9],"rows":[{"label":"Status","value":"neutral"},{"label":"Pattern","reference":"ref: how much of the distribution moved, not just the median","value":"mixed"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Quantile Shift"},{"code":"C3","effectQuantiles":null,"interpretation":"The change is below this test-specific threshold from recent master history of 27.4% (2.0% base, 13.7% history noise).","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"downgrade"},{"label":"Baseline floor","reference":"ref: timing default floor","value":"2.0%"},{"label":"History noise","reference":"ref: recent master noise","value":"13.7%"},{"label":"Adaptive threshold","reference":"ref: observed -15.3%","value":"27.4%"},{"label":"History points","reference":"latest usable points before this run, same architecture","value":"30"},{"label":"Latest history point","reference":"master history used for this verdict","value":"2026-09-26 04:57:32 UTC"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"downgrade","title":"History Adaptive Threshold"},{"code":"C4","effectQuantiles":null,"interpretation":"The slowdown is only somewhat larger than recent master variation.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Typical variation","reference":"same history-noise input used by C3; observed -15.3%","value":"13.7%"},{"label":"Slowdown / variation","reference":"observed slowdown divided by typical recent variation","value":"1.118"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Recent Master Variation"},{"code":"C5","effectQuantiles":null,"interpretation":"Historical series looks unimodal, so no fleet penalty was applied.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"neutral"},{"label":"Multimodal","value":"No"},{"label":"MValue","value":"2.370"},{"label":"Only one arch affected","value":"No"},{"label":"Affected arches","value":"1 / 1"},{"label":"Mode ratio","reference":"higher/lower mode centers within this architecture","value":"0.000"},{"label":"History snapshot","reference":"multimodality summaries are not timestamped; this is descriptive context, not an as-of snapshot","value":"Latest published"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"neutral","title":"Multimodality / Fleet"},{"code":"C6","effectQuantiles":null,"interpretation":"Nearby master runs show an unusual baseline-vs-PR contrast around this run.","newQuantiles":null,"oldQuantiles":null,"probabilities":null,"rows":[{"label":"Status","value":"supports"},{"label":"Window","reference":"later master runs and this commit are excluded","value":"72h before run"},{"label":"Nearby master runs","value":"43"},{"label":"PR reruns excluded","value":"0"},{"label":"Local level anomaly","reference":"baseline+PR level vs nearby master","value":"1.354"},{"label":"Baseline-vs-PR anomaly","reference":"old/new contrast vs nearby master","value":"6.171"},{"label":"Baseline-side anomaly","reference":"baseline side vs nearby master","value":"0.402"},{"label":"PR-side anomaly","reference":"PR side vs nearby master","value":"2.179"},{"label":"Baseline/PR dominance","reference":"positive = baseline side dominates, negative = PR side dominates","value":"-0.688"},{"label":"Architecture","reference":"evidence for this comparison row","value":"arm"}],"status":"supports","title":"Local Context"}],"reason":"The change is smaller than the threshold suggested by recent master history. Master runs show a slowdown this large often: 13.5% of the last 229 master runs (14 days) of this query showed a slowdown of at least 12.2%.","tier":"noise"},"diffPercent":-0.15299999713897705,"direction":"speedup","flakyLately":{"arch":"arm","asOfDay":"2026-09-26","directionFlip":true,"masterFlags":33,"metric":"client_time","negativeFlags":102,"positiveFlags":157,"prFlags":209,"queryIndex":2,"rank":28,"score":242,"test":"hashed_dictionary_load_factor","windowDays":14},"metric":"client_time","newValue":0.5332000255584717,"oldValue":0.6291999816894531,"queryDisplayName":"SYSTEM RELOAD DICTIONARY simple_key_HASHED_dictionary_l0_99","queryIndex":2,"reportLinks":[],"severity":"improvement","statThreshold":0.152,"test":"hashed_dictionary_load_factor"}]}
