Three things the 1,000-meter x 10-year measurement found, each proved by
EXPLAIN or a statement count before and after. No tally moves.
Freshness had two jobs in one unbounded query. The mark -- when a meter
last delivered -- is now stored on meter_rollup_state and maintained by
every recompute, with a one-pass backfill in the migration, so an
import-only meter keeps its years-old last activity without reading a
single raw row. The rhythm that decides stale versus live is sampled
inside a 90-day window and only for meters that actually have a live
source; a source silent for longer than that is re-read unbounded, so it
is still called stale by its own rhythm rather than by a default. The
portfolio query went from 13.8 ms planning plus 36.1 ms execution across
all 123 reading chunks to 0.58 plus 0.44 ms across four.
Window sums took their time bounds only from the unnest join, so the
planner could not exclude chunks: a 1,960-window case scanned 1.39 M rows
in parallel and spilled a 45 MB sort. Repeating the overall min and max as
constants makes it five chunks and nested-loop index scans, 121.5 ms to
8.7 ms.
The Overview read the catalog three times, once for the quantities and
once for each of its two bills. One context and one catalog snapshot now
feed all three: 31 statements per load to 23.
The final timings on an idle machine are in docs/ANALYSIS_REPORT.md: the
brief's target request (100 meters, ten years, monthly) is 286 ms against
two seconds, and a startup rebuild of 1,000 meters is 279 s.
The brief (§12) asks for a report: which of its findings A01-A14 were
fixed and how, how physical and virtual results now agree, which cost and
aggregation decisions were applied to existing data, what was tested, and
what is still missing. docs/ANALYSIS_REPORT.md is that, with a file path
and a pinning test for every row, the acceptance scenarios with their
evidence, the measured performance, and the limitations -- including the
three the note already records (raw retention not enforced, monthly
imports never interpolated, a full recompute per ingested reading) and the
three hotspots the measurement found.
The screenshots it references show the Overview, a physical and a virtual
meter, and an energy type's history at desktop and phone widths, plus two
"before" shots at c0f52db for comparison: the old Overview, and the old
virtual meter page, which offered a flow link instead of any analysis.
Florian Schmidt