Document the PostgreSQL schema contract in doc.go

cmd/weatherfeeder/main.go

@@ -15,9 +15,10 @@ import (
 	"gitea.maximumdirect.net/ejr/feedkit/config"
 	fkdispatch "gitea.maximumdirect.net/ejr/feedkit/dispatch"
 	fkevent "gitea.maximumdirect.net/ejr/feedkit/event"
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
 	fkpipeline "gitea.maximumdirect.net/ejr/feedkit/pipeline"
 	fkprocessors "gitea.maximumdirect.net/ejr/feedkit/processors"
+	fkdedupe "gitea.maximumdirect.net/ejr/feedkit/processors/dedupe"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 	fkscheduler "gitea.maximumdirect.net/ejr/feedkit/scheduler"
 	fksinks "gitea.maximumdirect.net/ejr/feedkit/sinks"
 	fksources "gitea.maximumdirect.net/ejr/feedkit/sources"
@@ -27,6 +28,8 @@ import (
 	wfsources "gitea.maximumdirect.net/ejr/weatherfeeder/internal/sources"
 )
 
+const dedupeMaxEntries = 2048
+
 func main() {
 	log.SetFlags(log.LstdFlags | log.Lmicroseconds)
 
@@ -103,9 +106,9 @@ func main() {
 
 	events := make(chan fkevent.Event, 256)
 
-	// --- Normalization (optional) ---
+	// --- Processors ---
 	//
-	// We install feedkit's normalize.Processor even before any normalizers exist.
+	// We install feedkit's processors/normalize.Processor even before any normalizers exist.
 	// With an empty normalizer list and RequireMatch=false, this is a no-op passthrough.
 	// It will begin transforming events as soon as:
 	//   1) sources emit raw schemas (raw.*), and
@@ -116,8 +119,9 @@ func main() {
 	procReg.Register("normalize", func() (fkprocessors.Processor, error) {
 		return fknormalize.NewProcessor(normalizers, false), nil
 	})
+	procReg.Register("dedupe", fkdedupe.Factory(dedupeMaxEntries))
 
-	chain, err := procReg.BuildChain([]string{"normalize"})
+	chain, err := procReg.BuildChain([]string{"normalize", "dedupe"})
 	if err != nil {
 		log.Fatalf("build processor chain failed: %v", err)
 	}

cmd/weatherfeeder/main_test.go

@@ -9,9 +9,10 @@ import (
 
 	"gitea.maximumdirect.net/ejr/feedkit/config"
 	fkevent "gitea.maximumdirect.net/ejr/feedkit/event"
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
 	fkpipeline "gitea.maximumdirect.net/ejr/feedkit/pipeline"
 	fkprocessors "gitea.maximumdirect.net/ejr/feedkit/processors"
+	fkdedupe "gitea.maximumdirect.net/ejr/feedkit/processors/dedupe"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 
 	wfnormalizers "gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers"
 )
@@ -97,39 +98,23 @@ func TestExampleConfigLoads(t *testing.T) {
 	}
 }
 
-func TestProcessorRegistryBuildsNormalizeChain(t *testing.T) {
+func TestProcessorRegistryBuildsNormalizeThenDedupeChain(t *testing.T) {
-	normalizers := wfnormalizers.RegisterBuiltins(nil)
+	chain, err := buildProcessorChainForTests()
-	if len(normalizers) == 0 {
-		t.Fatalf("RegisterBuiltins() returned no normalizers")
-	}
-
-	procReg := fkprocessors.NewRegistry()
-	procReg.Register("normalize", func() (fkprocessors.Processor, error) {
-		return fknormalize.NewProcessor(normalizers, false), nil
-	})
-
-	chain, err := procReg.BuildChain([]string{"normalize"})
 	if err != nil {
 		t.Fatalf("BuildChain() unexpected error: %v", err)
 	}
-	if len(chain) != 1 {
+	if len(chain) != 2 {
-		t.Fatalf("BuildChain() expected 1 processor, got %d", len(chain))
+		t.Fatalf("BuildChain() expected 2 processors, got %d", len(chain))
 	}
 
 	pl := &fkpipeline.Pipeline{Processors: chain}
-	if len(pl.Processors) != 1 {
+	if len(pl.Processors) != 2 {
-		t.Fatalf("pipeline expected 1 processor, got %d", len(pl.Processors))
+		t.Fatalf("pipeline expected 2 processors, got %d", len(pl.Processors))
 	}
 }
 
 func TestNormalizeNoMatchPassThrough(t *testing.T) {
-	normalizers := wfnormalizers.RegisterBuiltins(nil)
+	chain, err := buildProcessorChainForTests()
-	procReg := fkprocessors.NewRegistry()
-	procReg.Register("normalize", func() (fkprocessors.Processor, error) {
-		return fknormalize.NewProcessor(normalizers, false), nil
-	})
-
-	chain, err := procReg.BuildChain([]string{"normalize"})
 	if err != nil {
 		t.Fatalf("BuildChain() unexpected error: %v", err)
 	}
@@ -157,3 +142,50 @@ func TestNormalizeNoMatchPassThrough(t *testing.T) {
 		t.Fatalf("Pipeline.Process() expected passthrough output, got %#v", *out)
 	}
 }
+
+func TestDedupeDropsSecondEventWithSameID(t *testing.T) {
+	chain, err := buildProcessorChainForTests()
+	if err != nil {
+		t.Fatalf("BuildChain() unexpected error: %v", err)
+	}
+
+	pl := &fkpipeline.Pipeline{Processors: chain}
+	in := fkevent.Event{
+		ID:        "evt-dedupe-1",
+		Kind:      fkevent.Kind("observation"),
+		Source:    "test",
+		EmittedAt: time.Now().UTC(),
+		Schema:    "raw.weatherfeeder.unknown.v1",
+		Payload: map[string]any{
+			"ok": true,
+		},
+	}
+
+	first, err := pl.Process(context.Background(), in)
+	if err != nil {
+		t.Fatalf("first Pipeline.Process() unexpected error: %v", err)
+	}
+	if first == nil {
+		t.Fatalf("first Pipeline.Process() unexpectedly dropped event")
+	}
+
+	second, err := pl.Process(context.Background(), in)
+	if err != nil {
+		t.Fatalf("second Pipeline.Process() unexpected error: %v", err)
+	}
+	if second != nil {
+		t.Fatalf("second Pipeline.Process() expected dedupe drop, got %#v", *second)
+	}
+}
+
+func buildProcessorChainForTests() ([]fkprocessors.Processor, error) {
+	normalizers := wfnormalizers.RegisterBuiltins(nil)
+
+	procReg := fkprocessors.NewRegistry()
+	procReg.Register("normalize", func() (fkprocessors.Processor, error) {
+		return fknormalize.NewProcessor(normalizers, false), nil
+	})
+	procReg.Register("dedupe", fkdedupe.Factory(dedupeMaxEntries))
+
+	return procReg.BuildChain([]string{"normalize", "dedupe"})
+}

go.mod

@@ -2,10 +2,11 @@ module gitea.maximumdirect.net/ejr/weatherfeeder
 
 go 1.25
 
-require gitea.maximumdirect.net/ejr/feedkit v0.7.0
+require gitea.maximumdirect.net/ejr/feedkit v0.7.2
 
 require (
 	github.com/klauspost/compress v1.17.2 // indirect
+	github.com/lib/pq v1.10.9 // indirect
 	github.com/nats-io/nats.go v1.34.0 // indirect
 	github.com/nats-io/nkeys v0.4.7 // indirect
 	github.com/nats-io/nuid v1.0.1 // indirect

go.sum

@@ -1,7 +1,9 @@
-gitea.maximumdirect.net/ejr/feedkit v0.7.0 h1:qXbsD30BH1HkKf579B4Qu3pDiT9mr+8DmDwzd3IXUoo=
+gitea.maximumdirect.net/ejr/feedkit v0.7.2 h1:hTg302SgSi7tw11lNzuc+3g7MvHT6jQQziuo2NoARt8=
-gitea.maximumdirect.net/ejr/feedkit v0.7.0/go.mod h1:wYtA10GouvSe7L/8e1UEC+tqcp32HJofExIo1k+Wjls=
+gitea.maximumdirect.net/ejr/feedkit v0.7.2/go.mod h1:U6xC9xZLN3cL4yi7YBVyzGoHYRLJXusFCAKlj2kdYYQ=
 github.com/klauspost/compress v1.17.2 h1:RlWWUY/Dr4fL8qk9YG7DTZ7PDgME2V4csBXA8L/ixi4=
 github.com/klauspost/compress v1.17.2/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
+github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
+github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/nats-io/nats.go v1.34.0 h1:fnxnPCNiwIG5w08rlMcEKTUw4AV/nKyGCOJE8TdhSPk=
 github.com/nats-io/nats.go v1.34.0/go.mod h1:Ubdu4Nh9exXdSz0RVWRFBbRfrbSxOYd26oF0wkWclB8=
 github.com/nats-io/nkeys v0.4.7 h1:RwNJbbIdYCoClSDNY7QVKZlyb/wfT6ugvFCiKy6vDvI=

internal/normalizers/builtins.go

@@ -2,7 +2,7 @@
 package normalizers
 
 import (
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 
 	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/nws"
 	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/openmeteo"

internal/normalizers/builtins_test.go

@@ -4,7 +4,7 @@ import (
 	"reflect"
 	"testing"
 
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/nws"
 	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/openmeteo"
 	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/normalizers/openweather"

internal/normalizers/doc.go

@@ -29,7 +29,7 @@
 //
 //  1. One normalizer per file.
 //     Each file contains exactly one Normalizer implementation (one type that
-//     satisfies feedkit/normalize.Normalizer).
+//     satisfies feedkit/processors/normalize.Normalizer).
 //     Helper files are encouraged (types.go, common.go, mapping.go, etc.) as long
 //     as they do not define additional Normalizer types.
 //

internal/normalizers/nws/register.go

@@ -2,7 +2,7 @@
 package nws
 
 import (
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 )
 
 // Register appends NWS normalizers in stable order.

internal/normalizers/openmeteo/register.go

@@ -2,7 +2,7 @@
 package openmeteo
 
 import (
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 )
 
 // Register appends Open-Meteo normalizers in stable order.

internal/normalizers/openweather/register.go

@@ -2,7 +2,7 @@
 package openweather
 
 import (
-	fknormalize "gitea.maximumdirect.net/ejr/feedkit/normalize"
+	fknormalize "gitea.maximumdirect.net/ejr/feedkit/processors/normalize"
 )
 
 // Register appends OpenWeather normalizers in stable order.

internal/sinks/postgres/doc.go

@@ -0,0 +1,208 @@
+// Package postgres documents weatherfeeder's PostgreSQL sink contract for
+// downstream SQL consumers.
+//
+// This package wires weatherfeeder canonical events into normalized relational
+// tables. Downstream consumers can reconstruct the same canonical JSON objects
+// that were written by joining parent/child tables as described below.
+//
+// Canonical input schemas:
+//   - weather.observation.v1 -> model.WeatherObservation
+//   - weather.forecast.v1    -> model.WeatherForecastRun
+//   - weather.alert.v1       -> model.WeatherAlertRun
+//
+// Parent/child relationships:
+//   - observations.event_id -> observation_cloud_layers.event_id
+//   - observations.event_id -> observation_present_weather.event_id
+//   - forecasts.event_id    -> forecast_periods.run_event_id
+//   - alert_runs.event_id   -> alerts.run_event_id
+//   - alerts.(run_event_id, alert_index) -> alert_references.(run_event_id, alert_index)
+//
+// Dedupe and retention behavior:
+//   - Parent primary keys (event_id): observations, forecasts, alert_runs.
+//   - Child primary keys use positional indexes to preserve payload order.
+//   - Prune columns:
+//   - observations.observed_at
+//   - observation_cloud_layers.observed_at
+//   - observation_present_weather.observed_at
+//   - forecasts.issued_at
+//   - forecast_periods.issued_at
+//   - alert_runs.as_of
+//   - alerts.as_of
+//   - alert_references.as_of
+//
+// Envelope field mapping (shared parent columns)
+//
+// These columns exist on observations, forecasts, and alert_runs:
+//   - event_id TEXT -> event.id
+//   - event_kind TEXT -> event.kind
+//   - event_source TEXT -> event.source
+//   - event_schema TEXT -> event.schema
+//   - event_emitted_at TIMESTAMPTZ -> event.emitted_at
+//   - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
+//
+// Table contract
+//
+//  1. observations (PK: event_id)
+//
+//     - event_id TEXT -> event.id
+//     - event_kind TEXT -> event.kind
+//     - event_source TEXT -> event.source
+//     - event_schema TEXT -> event.schema
+//     - event_emitted_at TIMESTAMPTZ -> event.emitted_at
+//     - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
+//     - station_id TEXT NULL -> payload.stationId
+//     - station_name TEXT NULL -> payload.stationName
+//     - observed_at TIMESTAMPTZ -> payload.timestamp
+//     - condition_code INTEGER -> payload.conditionCode
+//     - condition_text TEXT NULL -> payload.conditionText
+//     - is_day BOOLEAN NULL -> payload.isDay
+//     - provider_raw_description TEXT NULL -> payload.providerRawDescription
+//     - text_description TEXT NULL -> payload.textDescription
+//     - icon_url TEXT NULL -> payload.iconUrl
+//     - temperature_c DOUBLE PRECISION NULL -> payload.temperatureC
+//     - dewpoint_c DOUBLE PRECISION NULL -> payload.dewpointC
+//     - wind_direction_degrees DOUBLE PRECISION NULL -> payload.windDirectionDegrees
+//     - wind_speed_kmh DOUBLE PRECISION NULL -> payload.windSpeedKmh
+//     - wind_gust_kmh DOUBLE PRECISION NULL -> payload.windGustKmh
+//     - barometric_pressure_pa DOUBLE PRECISION NULL -> payload.barometricPressurePa
+//     - sea_level_pressure_pa DOUBLE PRECISION NULL -> payload.seaLevelPressurePa
+//     - visibility_meters DOUBLE PRECISION NULL -> payload.visibilityMeters
+//     - relative_humidity_percent DOUBLE PRECISION NULL -> payload.relativeHumidityPercent
+//     - apparent_temperature_c DOUBLE PRECISION NULL -> payload.apparentTemperatureC
+//     - elevation_meters DOUBLE PRECISION NULL -> payload.elevationMeters
+//     - raw_message TEXT NULL -> payload.rawMessage
+//
+//  2. observation_cloud_layers (PK: event_id, layer_index)
+//
+//     - event_id TEXT -> observations.event_id / payload.cloudLayers[i]
+//     - layer_index INTEGER -> i (array position in payload.cloudLayers)
+//     - observed_at TIMESTAMPTZ -> payload.timestamp
+//     - base_meters DOUBLE PRECISION NULL -> payload.cloudLayers[i].baseMeters
+//     - amount TEXT NULL -> payload.cloudLayers[i].amount
+//
+//  3. observation_present_weather (PK: event_id, weather_index)
+//
+//     - event_id TEXT -> observations.event_id / payload.presentWeather[i]
+//     - weather_index INTEGER -> i (array position in payload.presentWeather)
+//     - observed_at TIMESTAMPTZ -> payload.timestamp
+//     - raw_text TEXT NULL -> JSON-encoded payload.presentWeather[i].raw
+//
+// Note: raw_text stores compact JSON text. Consumers that need the original
+// object should parse raw_text as JSON.
+//
+//  4. forecasts (PK: event_id)
+//
+//     - event_id TEXT -> event.id
+//     - event_kind TEXT -> event.kind
+//     - event_source TEXT -> event.source
+//     - event_schema TEXT -> event.schema
+//     - event_emitted_at TIMESTAMPTZ -> event.emitted_at
+//     - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
+//     - location_id TEXT NULL -> payload.locationId
+//     - location_name TEXT NULL -> payload.locationName
+//     - issued_at TIMESTAMPTZ -> payload.issuedAt
+//     - updated_at TIMESTAMPTZ NULL -> payload.updatedAt
+//     - product TEXT -> payload.product
+//     - latitude DOUBLE PRECISION NULL -> payload.latitude
+//     - longitude DOUBLE PRECISION NULL -> payload.longitude
+//     - elevation_meters DOUBLE PRECISION NULL -> payload.elevationMeters
+//     - period_count INTEGER -> len(payload.periods)
+//
+//  5. forecast_periods (PK: run_event_id, period_index)
+//
+//     - run_event_id TEXT -> forecasts.event_id / payload.periods[i]
+//     - period_index INTEGER -> i (array position in payload.periods)
+//     - issued_at TIMESTAMPTZ -> payload.issuedAt (copied from parent)
+//     - start_time TIMESTAMPTZ -> payload.periods[i].startTime
+//     - end_time TIMESTAMPTZ -> payload.periods[i].endTime
+//     - name TEXT NULL -> payload.periods[i].name
+//     - is_day BOOLEAN NULL -> payload.periods[i].isDay
+//     - condition_code INTEGER -> payload.periods[i].conditionCode
+//     - condition_text TEXT NULL -> payload.periods[i].conditionText
+//     - provider_raw_description TEXT NULL -> payload.periods[i].providerRawDescription
+//     - text_description TEXT NULL -> payload.periods[i].textDescription
+//     - detailed_text TEXT NULL -> payload.periods[i].detailedText
+//     - icon_url TEXT NULL -> payload.periods[i].iconUrl
+//     - temperature_c DOUBLE PRECISION NULL -> payload.periods[i].temperatureC
+//     - temperature_c_min DOUBLE PRECISION NULL -> payload.periods[i].temperatureCMin
+//     - temperature_c_max DOUBLE PRECISION NULL -> payload.periods[i].temperatureCMax
+//     - dewpoint_c DOUBLE PRECISION NULL -> payload.periods[i].dewpointC
+//     - relative_humidity_percent DOUBLE PRECISION NULL -> payload.periods[i].relativeHumidityPercent
+//     - wind_direction_degrees DOUBLE PRECISION NULL -> payload.periods[i].windDirectionDegrees
+//     - wind_speed_kmh DOUBLE PRECISION NULL -> payload.periods[i].windSpeedKmh
+//     - wind_gust_kmh DOUBLE PRECISION NULL -> payload.periods[i].windGustKmh
+//     - barometric_pressure_pa DOUBLE PRECISION NULL -> payload.periods[i].barometricPressurePa
+//     - visibility_meters DOUBLE PRECISION NULL -> payload.periods[i].visibilityMeters
+//     - apparent_temperature_c DOUBLE PRECISION NULL -> payload.periods[i].apparentTemperatureC
+//     - cloud_cover_percent DOUBLE PRECISION NULL -> payload.periods[i].cloudCoverPercent
+//     - probability_of_precipitation_percent DOUBLE PRECISION NULL -> payload.periods[i].probabilityOfPrecipitationPercent
+//     - precipitation_amount_mm DOUBLE PRECISION NULL -> payload.periods[i].precipitationAmountMm
+//     - snowfall_depth_mm DOUBLE PRECISION NULL -> payload.periods[i].snowfallDepthMm
+//     - uv_index DOUBLE PRECISION NULL -> payload.periods[i].uvIndex
+//
+//  6. alert_runs (PK: event_id)
+//
+//     - event_id TEXT -> event.id
+//     - event_kind TEXT -> event.kind
+//     - event_source TEXT -> event.source
+//     - event_schema TEXT -> event.schema
+//     - event_emitted_at TIMESTAMPTZ -> event.emitted_at
+//     - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
+//     - location_id TEXT NULL -> payload.locationId
+//     - location_name TEXT NULL -> payload.locationName
+//     - as_of TIMESTAMPTZ -> payload.asOf
+//     - latitude DOUBLE PRECISION NULL -> payload.latitude
+//     - longitude DOUBLE PRECISION NULL -> payload.longitude
+//     - alert_count INTEGER -> len(payload.alerts)
+//
+//  7. alerts (PK: run_event_id, alert_index)
+//
+//     - run_event_id TEXT -> alert_runs.event_id / payload.alerts[i]
+//     - alert_index INTEGER -> i (array position in payload.alerts)
+//     - as_of TIMESTAMPTZ -> payload.asOf (copied from parent)
+//     - alert_id TEXT -> payload.alerts[i].id
+//     - event TEXT NULL -> payload.alerts[i].event
+//     - headline TEXT NULL -> payload.alerts[i].headline
+//     - severity TEXT NULL -> payload.alerts[i].severity
+//     - urgency TEXT NULL -> payload.alerts[i].urgency
+//     - certainty TEXT NULL -> payload.alerts[i].certainty
+//     - status TEXT NULL -> payload.alerts[i].status
+//     - message_type TEXT NULL -> payload.alerts[i].messageType
+//     - category TEXT NULL -> payload.alerts[i].category
+//     - response TEXT NULL -> payload.alerts[i].response
+//     - description TEXT NULL -> payload.alerts[i].description
+//     - instruction TEXT NULL -> payload.alerts[i].instruction
+//     - sent TIMESTAMPTZ NULL -> payload.alerts[i].sent
+//     - effective TIMESTAMPTZ NULL -> payload.alerts[i].effective
+//     - onset TIMESTAMPTZ NULL -> payload.alerts[i].onset
+//     - expires TIMESTAMPTZ NULL -> payload.alerts[i].expires
+//     - area_description TEXT NULL -> payload.alerts[i].areaDescription
+//     - sender_name TEXT NULL -> payload.alerts[i].senderName
+//     - reference_count INTEGER -> len(payload.alerts[i].references)
+//
+//  8. alert_references (PK: run_event_id, alert_index, reference_index)
+//
+//     - run_event_id TEXT -> alert_runs.event_id / payload.alerts[i].references[j]
+//     - alert_index INTEGER -> i (array position in payload.alerts)
+//     - reference_index INTEGER -> j (array position in payload.alerts[i].references)
+//     - as_of TIMESTAMPTZ -> payload.asOf (copied from parent)
+//     - id TEXT NULL -> payload.alerts[i].references[j].id
+//     - identifier TEXT NULL -> payload.alerts[i].references[j].identifier
+//     - sender TEXT NULL -> payload.alerts[i].references[j].sender
+//     - sent TIMESTAMPTZ NULL -> payload.alerts[i].references[j].sent
+//
+// Reconstructing canonical JSON payloads
+//
+//   - WeatherObservation:
+//     read one row from observations, then join child rows by event_id ordered by
+//     layer_index / weather_index to rebuild cloudLayers and presentWeather arrays.
+//
+//   - WeatherForecastRun:
+//     read one row from forecasts, then join forecast_periods by run_event_id
+//     ordered by period_index to rebuild periods.
+//
+//   - WeatherAlertRun:
+//     read one row from alert_runs, join alerts by run_event_id ordered by
+//     alert_index, then join alert_references by (run_event_id, alert_index)
+//     ordered by reference_index to rebuild references per alert.
+package postgres