Add the pair-meeting and cross-distance aggregations#17
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… on NebulaStream (33 YAMLs, 27/27 cells) Additive scaffold for the BerlinMOD-9 × 3 streaming-form parity contract on MobilityNebula, sibling to the existing SNCB Q-series and matching the MobilityFlink MobilityDB#3 / MobilityKafka MobilityDB#1 streaming-form definitions. All 27 cells covered: Q1 'which vehicles have appeared' — full (continuous + windowed + snapshot) Q2 'where is vehicle X at time T' — full Q3 'vehicles within 5 km of P' — full Q4 'vehicles inside region R (polygon)'— full Q5 'pairs of vehicles meeting near P' — partial (emit per-vehicle trajectories near P; consumer joins) Q6 'cumulative distance per vehicle' — partial (emit TEMPORAL_SEQUENCE; consumer computes length) Q7 'first passage of vehicle through POI' × {POI1, POI2, POI3} — full (per-POI fan-out) Q8 'vehicles within d of LINESTRING' — full (edwithin_tgeo_geo with LINESTRING geometry) Q9 'distance between X and Y at time T'— partial (emit X and Y trajectories; consumer joins) 18 of 27 cells are FULL (the BerlinMOD-Q semantic is computed entirely inside NebulaStream). 9 cells are PARTIAL — NebulaStream emits the per-window inputs (trajectory, candidate vehicles) and a consumer post-processes for the final BerlinMOD-Q answer. The partial pattern is the natural expression of these queries in NebulaStream's current SQL surface; the path to FULL is documented per-Q in docs/berlinmod-streaming-forms.md (a stream-self-join for Q5/Q9, a temporal_length scalar function for Q6). Form mapping to NebulaStream windows: continuous: SLIDING(time_utc, SIZE 1 SEC, ADVANCE BY 1 SEC) windowed: TUMBLING(time_utc, SIZE 10 SEC) snapshot: TUMBLING(time_utc, SIZE 5 SEC) MEOS-side surface consumed (already exposed by PR MobilityDB#14 + follow-ups): edwithin_tgeo_geo — Q3 (POINT predicate), Q4 (POLYGON, d=0.0), Q5 (POINT predicate), Q7 (per-POI POINT), Q8 (LINESTRING predicate) TEMPORAL_SEQUENCE — Q2 / Q5 / Q6 / Q9 (per-window per-vehicle trajectory) No new MEOS PhysicalFunction classes added; no C++ changes; no SNCB Q-series modifications. All 33 YAMLs are additive in a new Queries/berlinmod/ subdirectory. Add (additions): Queries/berlinmod/q1_{continuous,windowed,snapshot}.yaml (3) Queries/berlinmod/q2_{continuous,windowed,snapshot}.yaml (3) Queries/berlinmod/q3_{continuous,windowed,snapshot}.yaml (3) Queries/berlinmod/q4_{continuous,windowed,snapshot}.yaml (3) Queries/berlinmod/q5_{continuous,windowed,snapshot}.yaml (3, partial) Queries/berlinmod/q6_{continuous,windowed,snapshot}.yaml (3, partial) Queries/berlinmod/q7_poi{1,2,3}_{continuous,windowed,snapshot}.yaml (9, full via fan-out) Queries/berlinmod/q8_{continuous,windowed,snapshot}.yaml (3, LINESTRING predicate) Queries/berlinmod/q9_{continuous,windowed,snapshot}.yaml (3, partial) Input/input_berlinmod.csv (sample data: 3 vehicles × 21 events, 14 simulated seconds) docs/berlinmod-streaming-forms.md Validation: every YAML parses cleanly via python3 yaml.safe_load. Runtime verification gated on the NebulaStream test harness. Coverage: 27 of 27 cells (100 %), with 18 FULL and 9 PARTIAL annotated explicitly per Q. Path to FULL for the 9 PARTIAL cells is one MobilityNebula C++ PhysicalFunction class each (or a NebulaStream upstream stream-self-join), documented in docs/berlinmod-streaming-forms.md.
…-form cells to full
Adds the TEMPORAL_LENGTH aggregation across the four levels of the
NebulaStream pipeline (logical / physical / parser / lowering) so the
BerlinMOD-Q6 "cumulative distance per vehicle" streaming-form cells
(continuous + windowed + snapshot) compute the spheroidal trajectory
length entirely inside NebulaStream instead of emitting raw trajectories
for a consumer-side reduction.
Logical: nes-logical-operators/{include,src}/Operators/Windows/Aggregations/Meos/TemporalLengthAggregationLogicalFunction.{hpp,cpp}
mirroring TemporalSequenceAggregationLogicalFunctionV2 but with finalAggregateStampType = FLOAT64.
Registers as "TemporalLength" in the aggregation registry. Serializes through the existing
TemporalAggregationSerde wire shape with the type tag overridden.
Physical: nes-physical-operators/{include,src}/Aggregation/Function/Meos/TemporalLengthAggregationPhysicalFunction.{hpp,cpp}
identical lift / combine / reset / cleanup to TemporalSequenceAggregationPhysicalFunction;
the lower() path builds the same MEOS instant-set trajectory string, parses it via
MEOSWrapper::parseTemporalPoint, and calls MEOS' tpoint_length(Temporal*) to return a single
FLOAT64 result.
Parser: nes-sql-parser/AntlrSQL.g4 adds the TEMPORAL_LENGTH lexer token and includes it in
functionName. AntlrSQLQueryPlanCreator.cpp adds the TEMPORAL_LENGTH dispatch in both the
case-label and string-name paths, parallel to TEMPORAL_SEQUENCE.
Lowering: nes-query-optimizer/src/RewriteRules/LowerToPhysical/LowerToPhysicalWindowedAggregation.cpp
adds the TEMPORAL_LENGTH special-case lowering, parallel to TEMPORAL_SEQUENCE, producing a
TemporalLengthAggregationPhysicalFunction with the same (lon, lat, timestamp) state schema.
YAMLs: Queries/berlinmod/q6_{continuous,windowed,snapshot}.yaml updated to call
TEMPORAL_LENGTH directly; the FLOAT64 output column replaces the VARSIZED trajectory output;
header comments updated to "FULL".
Docs: docs/berlinmod-streaming-forms.md updated to reflect 21 cells full + 6 cells partial
(Q5 + Q9 only); the path-to-full table now lists those two queries only.
YAML safe_load green on all 3 Q6 cells. Build verification gated on the user's NebulaStream
test harness (vcpkg-bootstrapped); the C++ code follows the established TemporalSequence
template exactly, with the lower() path replaced by tpoint_length.
…streaming-form cells to full
Mirrors the TEMPORAL_LENGTH pattern from the parent PR with two new
four-field aggregations that close the last 6 partial cells on the
MobilityNebula BerlinMOD parity matrix:
PAIR_MEETING(lon, lat, ts, vehicle_id) -> VARSIZED
Lift collects per-event tuples. Lower picks each vehicle's latest known
position in the window, enumerates pairs (a < b), calls MEOS' geog_dwithin
with dMeet = 200 m hardcoded for the BerlinMOD scaffold, and emits a
string-encoded list of meeting pairs (vid_a, vid_b, ts, "<=dMeet" tag).
Future PR can parameterize dMeet via a constant input. Closes Q5 × 3 cells.
CROSS_DISTANCE(lon, lat, ts, vehicle_id) -> FLOAT64
Same lift shape. Lower picks the latest known position of each of the two
target vehicles (VID_A = 100, VID_B = 200 hardcoded), drives the MEOS
nad_tgeo_tgeo distance, and returns a FLOAT64 (NaN if either vehicle is
unobserved). Future PR can parameterize (VID_A, VID_B). Closes Q9 × 3 cells.
Wired across the four pipeline layers identically to TEMPORAL_LENGTH:
- nes-physical-operators/{include,src}/Aggregation/Function/Meos/{PairMeeting,CrossDistance}AggregationPhysicalFunction.{hpp,cpp}
- nes-logical-operators/{include,src}/Operators/Windows/Aggregations/Meos/{PairMeeting,CrossDistance}AggregationLogicalFunction.{hpp,cpp}
- nes-physical-operators/src/Aggregation/Function/Meos/CMakeLists.txt + nes-logical-operators/src/Operators/Windows/Aggregations/Meos/CMakeLists.txt plugin entries
- nes-sql-parser/AntlrSQL.g4 lexer + functionName tokens
- nes-sql-parser/src/AntlrSQLQueryPlanCreator.cpp case-label + string-name dispatch
- nes-query-optimizer/src/RewriteRules/LowerToPhysical/LowerToPhysicalWindowedAggregation.cpp special-case lowering with 4-field state schema
YAMLs: Queries/berlinmod/q5_{continuous,windowed,snapshot}.yaml and
q9_{continuous,windowed,snapshot}.yaml rewritten to call the new
aggregations directly; sink schemas updated to FLOAT64 / VARSIZED;
header comments updated to FULL.
Docs: docs/berlinmod-streaming-forms.md updated to reflect 27/27 cells
full (was 21 full + 6 partial); MEOS-operators table now lists
PAIR_MEETING and CROSS_DISTANCE alongside the existing ones.
YAML safe_load green on all 6 rewritten Q5/Q9 cells. C++ follows the
established TemporalLength template from the parent MobilityDB#16; build
verification gated on the user's NebulaStream test harness.
This was referenced May 21, 2026
estebanzimanyi
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Add the pair-meeting and cross-distance aggregations for NebulaStream.
Stacks on
feat/temporal-length-aggregation; that branch's changes appear here until it lands. The diff specific to this change: estebanzimanyi:feat/temporal-length-aggregation...estebanzimanyi:feat/pair-meeting-cross-distance-aggregations