Merge pull request #179 from EURODEO/extent-performance

Remove filtering parameters from GetExtents.

datastore/datastore/storagebackend/postgresql/getextents.go

@@ -5,85 +5,80 @@ import (
 	"datastore/common"
 	"datastore/datastore"
 	"fmt"
+	"time"
 
 	_ "github.com/lib/pq"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
-// createExtQueryVals creates from request values used for querying extentions.
-//
-// Values to be used for query placeholders are appended to phVals.
-//
-// Upon success the function returns two values:
-// - time filter used in a 'WHERE ... AND ...' clause
-// - string metadata ... ditto
-// - nil,
-// otherwise (..., ..., error).
-func createExtQueryVals(request *datastore.GetExtentsRequest, phVals *[]interface{}) (
-	string, string, error) {
+// getTemporalExtent gets the current temporal extent of all observations in the storage.
+func getTemporalExtent(db *sql.DB) (*datastore.TimeInterval, error) {
+	query := "SELECT min(obstime_instant), max(obstime_instant) FROM observation"
+	row := db.QueryRow(query)
+
+	var start, end time.Time
+
+	err := row.Scan(&start, &end)
+	if err != nil {
+		return nil, fmt.Errorf("row.Scan() failed: %v", err)
+	}
 
 	loTime, hiTime := common.GetValidTimeRange()
-	timeFilter := fmt.Sprintf(`
-		((obstime_instant >= to_timestamp(%d)) AND (obstime_instant <= to_timestamp(%d)))
-	`, loTime.Unix(), hiTime.Unix())
+	if start.Before(loTime) {
+		start = loTime
+	}
+	if end.After(hiTime) {
+		end = hiTime
+	}
 
-	stringMdataFilter, err := getStringMdataFilter(request.GetFilter(), phVals)
+	return &datastore.TimeInterval{
+		Start: timestamppb.New(start),
+		End:   timestamppb.New(end),
+	}, nil
+}
+
+// getSpatialExtent gets the current horizontally spatial extent of all observations in the storage.
+func getSpatialExtent(db *sql.DB) (*datastore.BoundingBox, error) {
+	query := `
+		SELECT ST_XMin(ext), ST_YMin(ext), ST_XMax(ext), ST_YMax(ext)
+		FROM (SELECT ST_Extent(point::geometry) AS ext FROM geo_point) t
+	`
+	row := db.QueryRow(query)
+
+	var xmin, ymin, xmax, ymax float64
+
+	err := row.Scan(&xmin, &ymin, &xmax, &ymax)
 	if err != nil {
-		return "", "", fmt.Errorf("getStringMdataFilter() failed: %v", err)
+		return nil, fmt.Errorf("row.Scan() failed: %v", err)
 	}
 
-	return timeFilter, stringMdataFilter, nil
+	return &datastore.BoundingBox{
+		Left:   xmin,
+		Bottom: ymin,
+		Right:  xmax,
+		Top:    ymax,
+	}, nil
 }
 
 // GetExtents ... (see documentation in StorageBackend interface)
-func (sbe *PostgreSQL) GetExtents(request *datastore.GetExtentsRequest) (
+func (sbe *PostgreSQL) GetExtents(_ *datastore.GetExtentsRequest) (
 	*datastore.GetExtentsResponse, codes.Code, string) {
 
-	// get values needed for query
-	phVals := []interface{}{} // placeholder values
-	timeFilter, stringMdataFilter, err := createExtQueryVals(request, &phVals)
+	var err error
+
+	temporalExtent, err := getTemporalExtent(sbe.Db)
 	if err != nil {
-		return nil, codes.Internal, fmt.Sprintf("createQueryVals() failed: %v", err)
+		return nil, codes.Internal, fmt.Sprintf("getTemporalExtent() failed: %v", err)
 	}
 
-	query := fmt.Sprintf(`
-		SELECT temp_min, temp_max,
-			ST_XMin(spat_ext), ST_YMin(spat_ext), ST_XMax(spat_ext), ST_YMax(spat_ext)
-		FROM (
-			SELECT min(obstime_instant) AS temp_min, max(obstime_instant) AS temp_max,
-				ST_Extent(point::geometry) AS spat_ext
-			FROM observation
-			JOIN time_series ON observation.ts_id = time_series.id
-			JOIN geo_point ON observation.geo_point_id = geo_point.id
-			WHERE %s AND %s
-		) t
-	`, timeFilter, stringMdataFilter)
-
-	row := sbe.Db.QueryRow(query, phVals...)
-
-	var (
-		start, end             sql.NullTime
-		xmin, ymin, xmax, ymax float64
-	)
-
-	err = row.Scan(&start, &end, &xmin, &ymin, &xmax, &ymax)
-	if !start.Valid { // indicates no matching rows found!
-		return nil, codes.NotFound, "no matching data to compute extensions for"
-	} else if err != nil {
-		return nil, codes.Internal, fmt.Sprintf("row.Scan() failed: %v", err)
+	spatialExtent, err := getSpatialExtent(sbe.Db)
+	if err != nil {
+		return nil, codes.Internal, fmt.Sprintf("getSpatialExtent() failed: %v", err)
 	}
 
 	return &datastore.GetExtentsResponse{
-		TemporalExtent: &datastore.TimeInterval{
-			Start: timestamppb.New(start.Time),
-			End:   timestamppb.New(end.Time),
-		},
-		SpatialExtent: &datastore.BoundingBox{
-			Left:   xmin,
-			Bottom: ymin,
-			Right:  xmax,
-			Top:    ymax,
-		},
+		TemporalExtent: temporalExtent,
+		SpatialExtent:  spatialExtent,
 	}, codes.OK, ""
 }

datastore/migrate/data/migrations/1726758806_obstime_index.down.sql

@@ -0,0 +1 @@
+DROP INDEX CONCURRENTLY observation_obstim_instant;

datastore/migrate/data/migrations/1726758806_obstime_index.up.sql

@@ -0,0 +1 @@
+CREATE INDEX CONCURRENTLY observation_obstime_instant ON observation (obstime_instant);

protobuf/datastore.proto

@@ -257,13 +257,7 @@ message GetTSAGResponse {
 //---------------------------------------------------------------------------
 
 message GetExtentsRequest {
-  // --- BEGIN string metadata (handleable with reflection) -------------------------
-
-  // general filter
-  // - map keys must correspond exactly with string field names in TSMetadata or ObsMetadata
-  // - if map key F is specified (where F is for example 'platform'), only observations that match
-  //   at least one of these values for F may be returned
-  map<string, Strings> filter = 1;
+  // No parameters
 
   // --- END string metadata (handleable with reflection) -------------------------
 }