pg_orrery v0.7.0 SP-GiST Benchmark — 66k Full Space-Track Catalog
===================================================================
Date: 2026-02-17
Catalog: Space-Track USSPACECOM full catalog including decayed (65,886 objects)
Host: Linux 6.16.5-arch1-1, PostgreSQL 17
Branch: phase/spgist-orbital-trie
Note: After fixing L1 inclination pruning (sma_low -> sma_high)

Catalog Composition:
  LEO (<128 min):          59,537  (90.4%)
  MEO (128-720 min):        3,474  ( 5.3%)
  GEO/HEO (720-1500 min):  2,643  ( 4.0%)
  Super-GEO (>1500 min):     232  ( 0.4%)

Index Build:
  SP-GiST: 55.2 ms, 11 MB
  GiST:   118.2 ms, 13 MB
  Table:              10 MB

==============================================================
TIMING RESULTS (best of 2-3 runs, ms)
==============================================================

Query Pattern                | Seqscan | SP-GiST | Delta
-----------------------------|---------|---------|-------
2h window, Eagle ID, 10 deg  |  12.5   |  14.0   | +1.5
6h window, Eagle ID, 10 deg  |  12.2   |  15.6   | +3.4
2h window, Tromsø, 10 deg    |  11.3   |  10.9   | -0.4  ★
24h window, Eagle ID, 10 deg |  12.0   |  16.2   | +4.2

★ Tromsø (69.6°N): SP-GiST beats seqscan. High-latitude observers
  benefit most from inclination pruning.

==============================================================
PRUNING RESULTS
==============================================================

Query Pattern                | Candidates | % Pass | % Pruned
-----------------------------|------------|--------|---------
2h window, Eagle ID, 10 deg  |   12,964   |  19.7% |   80.3%
6h window, Eagle ID, 10 deg  |   24,274   |  36.8% |   63.2%
24h window, Eagle ID, 10 deg |   60,875   |  92.4% |    7.6%
2h window, Eagle ID, 30 deg  |    9,680   |  14.7% |   85.3%
2h window, equatorial, 10deg |    9,699   |  14.7% |   85.3%
2h window, Tromsø 69.6°N     |    6,529   |   9.9% |   90.1%
2h window, South Pole 85°S   |    5,248   |   8.0% |   92.0%

==============================================================
CONSISTENCY CHECKS (all patterns)
==============================================================

Query Pattern                | False Negatives | False Positives
-----------------------------|-----------------|----------------
2h Eagle 10deg               |        0        |       0
6h Eagle 10deg               |        0        |       0
24h Eagle 10deg              |        0        |       0
2h Eagle 30deg               |        0        |       0
2h Equator 10deg             |        0        |       0
2h Tromsø 10deg              |        0        |       0
2h South Pole 10deg          |        0        |       0

==============================================================
SCALING TREND (2h Eagle 10deg, best-of-N)
==============================================================

Catalog Size | Seqscan | SP-GiST | Delta  | Notes
-------------|---------|---------|--------|------
14,376       |  4.5 ms |  6.1 ms | +1.6ms | Active CelesTrak
29,784       |  5.2 ms |  5.2 ms | +0.0ms | Active Space-Track (before fix)
65,886       | 12.5 ms | 14.0 ms | +1.5ms | Full catalog incl decayed (after fix)

The fix (sma_high instead of sma_low for footprint) adds ~1-2ms overhead
by conservatively keeping more subtrees alive during L1 pruning. This is
the correct trade-off: zero false negatives is non-negotiable.

==============================================================
PLANNER BEHAVIOR (66k)
==============================================================

PostgreSQL still chooses SP-GiST Index Only Scan by default:
  Index Only Scan using bench_spgist on bench_catalog
    Index Cond: (tle &? ...)
    Heap Fetches: 0
    Buffers: shared hit=4990

Seqscan would read 1,297 pages. Index reads 4,990 pages (3.8x more).
But Index Only Scan avoids all heap I/O.

==============================================================
KEY FINDING: HIGH-LATITUDE OBSERVERS
==============================================================

The SP-GiST index is most valuable for high-latitude observers:

  Tromsø (69.6°N): 90.1% pruned, SP-GiST BEATS seqscan by 0.4ms
  South Pole (85°S): 92.0% pruned

High-latitude locations eliminate most LEO satellites via the
inclination filter — only satellites with inc > ~60° can reach
these latitudes. The SP-GiST trie prunes entire inclination
subtrees at L1, making the index scan faster than touching
every page in the table.

==============================================================
WHAT THE 80-92% PRUNING MEANS IN PRACTICE
==============================================================

For a 65,886-object catalog with a 2-hour window:
  - Without &? operator: 65,886 SGP4 predict_passes() calls
  - With &? operator:    12,964 SGP4 calls (Eagle) or 5,248 (South Pole)
  - Savings: 52,922-60,638 unnecessary propagation calls avoided

At ~1ms per predict_passes() call (7-day window, 30s resolution),
that's 53-61 seconds of saved computation per query.