Add minDistance UDFs and adopt spatial-min Q5 form

.github/workflows/maven.yml

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+name: Maven CI
+
+on:
+  push:
+    branches: ["main", "feat/**", "fix/**"]
+    paths-ignore:
+      - "**/*.md"
+      - "doc/**"
+  pull_request:
+    branches: ["main", "feat/**", "fix/**"]
+    paths-ignore:
+      - "**/*.md"
+      - "doc/**"
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Build and test (Java 21 / Spark 3.5)
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Java 21
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "21"
+          cache: maven
+
+      - name: Install libmeos runtime dependencies
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y libjson-c5 libgeos-c1t64 libproj25 libgsl27
+
+      - name: Set up libmeos.so and LD_LIBRARY_PATH
+        run: |
+          mkdir -p /tmp/libmeos
+          cp "$GITHUB_WORKSPACE/lib/libmeos.so" /tmp/libmeos/libmeos.so
+          echo "LD_LIBRARY_PATH=/tmp/libmeos" >> "$GITHUB_ENV"
+
+      - name: Install JMEOS 1.4 to local Maven repository
+        run: |
+          mvn install:install-file \
+            -Dfile=libs/JMEOS-1.4.jar \
+            -DgroupId=org.jmeos \
+            -DartifactId=jmeos \
+            -Dversion=1.4 \
+            -Dpackaging=jar \
+            -q
+
+      - name: License header check
+        run: bash tools/scripts/check_license.sh
+
+      - name: Compile
+        run: mvn -B compile
+
+      - name: Unit tests
+        run: mvn -B test
+
+      - name: Package (fat jar)
+        run: mvn -B package -DskipTests
+
+      - name: Upload fat jar
+        uses: actions/upload-artifact@v4
+        with:
+          name: mobilityspark-spark.jar
+          path: target/*-spark.jar

.gitignore

@@ -3,14 +3,21 @@
 .project
 .settings/
 
-# Intellij
+# IntelliJ IDEA
 .idea/
 *.iml
 *.iws
+*.ipr
 
-# Mac
+# macOS
 .DS_Store
+**/.DS_Store
 
 # Maven
 log/
 target/
+
+# Large BerlinMOD benchmark data (generated locally — too large for GitHub)
+berlinmod/data/trips.csv
+dependency-reduced-pom.xml
+hs_err_pid*.log

LICENSE

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+-------------------------------------------------------------------------------
+This MobilityDB code is provided under The PostgreSQL License.
+
+Copyright (c) 2020-2025, Université libre de Bruxelles and MobilityDB
+contributors
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose, without fee, and without a written agreement is
+hereby granted, provided that the above copyright notice and this paragraph and
+the following two paragraphs appear in all copies.
+
+IN NO EVENT SHALL UNIVERSITE LIBRE DE BRUXELLES BE LIABLE TO ANY PARTY FOR
+DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION,
+EVEN IF UNIVERSITE LIBRE DE BRUXELLES HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+UNIVERSITE LIBRE DE BRUXELLES SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND
+UNIVERSITE LIBRE DE BRUXELLES HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
+SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

berlinmod/README.md

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+# BerlinMOD Portable SQL — Cross-Platform Verification
+
+This directory contains BerlinMOD benchmark queries in the **RFC #861 portable
+dialect** — using named functions only, no MobilityDB-specific operator symbols.
+The same SQL files run unchanged on all three platforms.
+
+| Platform | Engine | Extension |
+|---|---|---|
+| [MobilityDB](https://github.com/MobilityDB/MobilityDB) | PostgreSQL | `CREATE EXTENSION mobilitydb` |
+| [MobilityDuck](https://github.com/MobilityDB/MobilityDuck) | DuckDB | `LOAD mobilitydb` (community) |
+| [MobilitySpark](https://github.com/MobilityDB/MobilitySpark) | Apache Spark | `MobilitySparkSession.create(spark)` |
+
+---
+
+## Schema
+
+All three platforms use the same schema:
+
+```
+Vehicles      (vehId INT, licence TEXT, type TEXT, model TEXT)
+Trips         (tripId INT, vehId INT, trip TEXT)   -- tgeompoint hex-WKB
+QueryLicences (licenceId INT, licence TEXT)
+QueryInstants (instantId INT, instant TIMESTAMPTZ)
+QueryPoints   (pointId INT, geom TEXT)             -- geometry WKT, SRID 0
+QueryRegions  (regionId INT, geom TEXT)            -- polygon WKT, SRID 0
+QueryPeriods  (periodId INT, period TEXT)          -- tstzspan literal
+```
+
+**Storage conventions:**
+- `tgeompoint` values → hex-WKB STRING (`temporal_as_hexwkb` / `temporal_from_hexwkb`)
+- `geometry` / polygon values → WKT STRING, parsed via `geo_from_text` / `ST_GeomFromText`
+- `tstzspan` values → literal STRING `"[t1,t2]"`, cast to `tstzspan` by each platform
+
+Storing temporal/geometry values as portable text keeps the CSV files
+human-readable across all platforms without requiring platform-specific binary
+encoding.
+
+---
+
+## Queries
+
+| File | Query | Temporal operations |
+|------|-------|---------------------|
+| `q01.sql` | Vehicle models for query licences | none (baseline relational join) |
+| `q02.sql` | Licence plates of vehicles that ever entered a query region | `eIntersects(tgeompoint, geometry)` |
+| `q03.sql` | Position of query-licence vehicles at each query instant | `atTime(tgeompoint, timestamptz)` |
+| `q04.sql` | Vehicles that ever passed a query point | `eIntersects(tgeompoint, geometry)` |
+| `q05.sql` | Min nearest-approach distance between query-licence pairs | `nearestApproachDistance(tgeompoint, tgeompoint)` |
+| `q06.sql` | Truck pairs within 10 m | `eDwithin(tgeompoint, tgeompoint, float)` |
+| `q07.sql` | Trip portions of query-licence vehicles during each query period | `atTime(tgeompoint, tstzspan)` |
+| `q08.sql` | Trajectory geometry of each trip | `trajectory(tgeompoint)` |
+| `q09.sql` | Longest distance driven by any vehicle in each query period | `atTime`, `length` |
+| `q10.sql` | When did query-licence vehicles meet others (within 3 m)? | `expandSpace`, `tDwithin`, `whenTrue` |
+| `q11.sql` | Vehicles passing a query point at a query instant | `valueAtTimestamp`, `stbox` |
+| `q12.sql` | Vehicle pairs at the same query point at the same query instant | `valueAtTimestamp`, `stbox` |
+| `q13.sql` | Vehicles that travelled within a query region during a query period | `atTime`, `eIntersects`, `stbox` |
+| `q14.sql` | Vehicles inside a query region at a query instant | `valueAtTimestamp`, `ST_Contains`, `stbox` |
+| `q15.sql` | Vehicles that passed a query point during a query period | `atTime`, `eIntersects`, `stbox` |
+| `q16.sql` | Query-licence vehicle pairs in same region+period but always disjoint | `atTime`, `eIntersects`, `aDisjoint` |
+| `q17.sql` | Query points visited by the most distinct vehicles | `eIntersects` |
+| `qrt.sql` | Binary roundtrip — all trips serialised as hex-WKB | `asHexWKB(tgeompoint)` |
+
+`atTime` is polymorphic: pass a `TIMESTAMPTZ` (Q3) or a `tstzspan` literal (Q7)
+and the platform routes to the appropriate MEOS function.
+
+---
+
+## Shared dataset
+
+`data/` contains CSV files that all three platforms load:
+
+| File | Description |
+|------|-------------|
+| `data/vehicles.csv` | 5 vehicles (3 passenger, 2 truck) |
+| `data/trips.csv` | 5 trips, each as a tgeompoint hex-WKB string (SRID 0) |
+| `data/query_licences.csv` | 2 query licences |
+| `data/query_instants.csv` | 1 query instant |
+| `data/query_points.csv` | 2 query points (WKT) |
+| `data/query_regions.csv` | 1 query polygon region (WKT) |
+| `data/query_periods.csv` | 1 query period (tstzspan literal) |
+
+**Dataset design (SRID 0, planar):**
+
+```
+trip1 (B-AA 100): (0,0) → (100,0)  y = 0
+trip2 (B-BB 200): (0,5) → (100,5)  y = 5
+trip3 (B-CC 300): (0,3) → (100,3)  y = 3  (truck)
+trip4 (B-DD 400): (0,4) → (100,4)  y = 4  (truck, 1 unit from trip3)
+trip5 (B-EE 500): far away          (not near others)
+
+QueryPoints:  POINT(50 0), POINT(50 5)
+QueryRegions: POLYGON((40 -1,60 -1,60 6,40 6,40 -1))  covers x=40..60, y=-1..6
+QueryPeriods: [2020-01-01 00:02:00+00, 2020-01-01 00:08:00+00]
+All trips active during: 2020-01-01 00:00 – 00:10 UTC
+```
+
+**Expected results (verified on MobilityDuck/DuckDB with toy dataset):**
+
+| Query | Result |
+|-------|--------|
+| Q1 | B-AA 100 → Sedan ; B-CC 300 → Lorry |
+| Q2 | B-AA 100, B-BB 200, B-CC 300, B-DD 400 (all 4 non-remote vehicles) |
+| Q3 | 2 rows — MEOS hex-WKB of position at 00:05 UTC |
+| Q4 | B-AA 100, B-BB 200 |
+| Q5 | B-AA 100 ↔ B-CC 300 : 3.0 (nearest approach distance) |
+| Q6 | B-CC 300 ↔ B-DD 400 (trucks within 10 m) |
+| Q7 | 2 rows — hex-WKB of trip portions during the query period |
+| Q8 | 5 rows — WKT trajectory geometry for each trip |
+| Q9 | 1 row — vehicle 5 (EE 500) covers max distance (600 units) in the query period |
+| Q10 | 4 meetings — B-AA 100 meets vehicle 3; B-CC 300 meets vehicles 1, 2, and 4 |
+| Q11 | 2 rows — B-AA 100 at POINT(50 0); B-BB 200 at POINT(50 5) at 00:05 |
+| Q12 | 0 rows — no two vehicles at the same point at the same instant |
+| Q13 | 4 rows — vehicles AA/BB/CC/DD all traverse the query region in the query period |
+| Q14 | 4 rows — same 4 vehicles inside the query region at 00:05 |
+| Q15 | 2 rows — B-AA 100 passes POINT(50 0); B-BB 200 passes POINT(50 5) in the period |
+| Q16 | 1 row — query-licence pair AA/CC in region during period but always spatially disjoint |
+| Q17 | 2 rows — both query points tied at 1 vehicle visit each |
+| QRT | 5 rows — MEOS hex-WKB of all 5 trips (binary roundtrip) |
+
+Expected CSV files for all queries are in `expected/`.
+
+**Cross-platform portability design:**
+- Q3 / Q7 / QRT: use `asHexWKB()` → `temporal_as_hexwkb(ptr, 0)` — byte-for-byte identical
+- Q8: uses `trajectory()` → `geo_as_hexewkb(ptr, NULL)` (PostgreSQL COPY, DuckDB COPY, and MobilitySpark UDF all produce the same little-endian WKB hex)
+- Q11/Q12/Q15: use `p.geomWKT` (original WKT text from CSV) instead of `ST_AsText(geom)` to avoid `POINT(x y)` vs `POINT (x y)` format divergence between PostGIS and DuckDB spatial
+- All other queries: boolean / integer / float / text outputs — identical across platforms
+
+---
+
+## Running on MobilityDB (PostgreSQL)
+
+```bash
+# Create a database and run the comparison:
+createdb berlinmod_portability
+./berlinmod/run_mbdb.sh berlinmod_portability
+```
+
+---
+
+## Running on MobilityDuck (DuckDB)
+
+```bash
+# Run from the repository root:
+./berlinmod/run_mduck.sh [path/to/duckdb]
+```
+
+---
+
+## Running on MobilitySpark (Apache Spark)
+
+```bash
+./berlinmod/run_mspark.sh [spark-submit-binary]
+```
+
+Or manually:
+
+```bash
+ulimit -c 0   # suppress multi-GB core dumps on native-library crashes
+spark-submit \
+  --class org.mobilitydb.spark.demo.BerlinMODDemo \
+  --master "local[2]" \
+  --conf "spark.driver.extraJavaOptions=-Djava.library.path=/usr/local/lib" \
+  target/mobilityspark-*-spark.jar \
+  berlinmod/data \
+  berlinmod/expected
+```
+
+---
+
+## Replacing the synthetic dataset with real BerlinMOD data
+
+The shared CSV format is produced directly by
+[MobilityDB-BerlinMOD](https://github.com/MobilityDB/MobilityDB-BerlinMOD)
+via `berlinmod_portability_export()`:
+
+```sql
+-- In a PostgreSQL database with generated BerlinMOD data:
+\i BerlinMOD/berlinmod_export.sql
+SELECT berlinmod_portability_export('/path/to/output/');
+```
+
+This writes `vehicles.csv`, `trips.csv`, `query_licences.csv`,
+`query_instants.csv`, `query_points.csv`, `query_regions.csv`, and
+`query_periods.csv` in exactly the schema expected by the comparison scripts.
+
+Replace `data/*.csv` with the generated files and re-run:
+
+```bash
+./berlinmod/run_mbdb.sh berlinmod_portability   # MobilityDB
+./berlinmod/run_mduck.sh                         # MobilityDuck
+./berlinmod/run_mspark.sh                        # MobilitySpark
+```

berlinmod/bench/.gitignore

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+# Machine-specific benchmark results — do not commit
+results/*.json
+results/report.md
+
+# DuckDB scratch database
+/tmp/berlinmod_bench.duckdb