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discord9andDennis Zhuang
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* perf(promql): reuse sliding min and max candidates Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com> * test(promql): simplify extrema benchmark parameters Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com> * test(promql): record baseline sliding extrema SQL results Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com> * perf(promql): rescan windows that barely overlap Reusing candidates loses to a plain scan when consecutive windows overlap little: the deque bookkeeping then costs more than the rescan it replaces. A local Criterion run on 4096 samples at width 240 / step 240 measured 10.79 -> 22.14 us for min and 12.83 -> 19.85 us for max. Pick the evaluator once per batch from the first two windows. RangeManipulate emits one window length and one step per batch, so that sample decides for all of them, and both evaluators return identical bits, so a wrong pick costs time only. Batches that do not qualify fold each window on its own. Move the incremental state into SlidingExtrema so tests can drive it directly: the exhaustive four-sample differential test cannot reach it through a UDF call, because such a batch never qualifies for reuse. Signed-off-by: Dennis Zhuang <xzhuang@greptime.com> * fix(promql): select the extrema evaluator from batch averages Reading the window shape off the first two windows misreads the batch. RangeManipulate starts a series at max(query start, first aligned sample), so a series that begins inside the query range gets a first window covering roughly one step, and a window covering no sample at all is emitted as (0, 0). Either one closed the gate for the whole batch, including the one-hour window at a 15s step that candidate reuse was written for. Compare the batch averages instead: at least 32 samples per window, and a step advancing at most a quarter of that. Uniform batches select exactly as before, so the thresholds keep the meaning they were measured with. The 32-sample rule had also moved most of the benchmark and query-regression shapes onto the rescan, including the case built to measure reset and rebuild. Widen those windows to 40 samples, add a step at the selection boundary, and add an end-to-end case with 40-sample windows advancing 5. Signed-off-by: Dennis Zhuang <xzhuang@greptime.com> * fix(promql): ignore empty windows when measuring batch advance The advance was read from the first and last window offsets, but a window covering no sample is emitted as (0, 0). A query whose last evaluation lands exactly one window past the last sample ends on such a window, and its zero offset made a batch of disjoint windows look like one that never moved, which selected the evaluator built for overlap. Results stayed correct; the cost was deque bookkeeping on the shape the scan fallback exists for. Take the offset span over the windows that cover a sample. Empty windows stay in the window count, where they only make both conditions stricter. Signed-off-by: Dennis Zhuang <xzhuang@greptime.com> --------- Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com> Signed-off-by: Dennis Zhuang <xzhuang@greptime.com> Co-authored-by: Dennis Zhuang <xzhuang@greptime.com>