Merge pull request #362 from entur/refactor/farezone-query-search-builder

Fix fareZones query timeout by replacing correlated subquery with JOIN

Author: assadriaz

src/main/java/org/rutebanken/tiamat/repository/search/FareZoneQueryFromSearchBuilder.java

@@ -37,7 +37,18 @@ public class FareZoneQueryFromSearchBuilder {
 
     public Pair<String, Map<String, Object>> buildQueryFromSearch(FareZoneSearch search) {
 
-        StringBuilder queryString = new StringBuilder("select f.* from fare_zone f ");
+        StringBuilder queryString = new StringBuilder("""
+                SELECT f.*
+                FROM fare_zone f
+                INNER JOIN (
+                    SELECT fv.netex_id, MAX(fv.version) AS max_version
+                    FROM fare_zone fv
+                    WHERE (fv.to_date IS NULL OR fv.to_date > NOW())
+                      AND (fv.from_date IS NULL OR fv.from_date < NOW())
+                    GROUP BY fv.netex_id
+                ) latest_fv ON f.netex_id = latest_fv.netex_id
+                          AND f.version = latest_fv.max_version
+                """);
         List<String> wheres = new ArrayList<>();
         List<String> operators = new ArrayList<>();
         List<String> orderByStatements = new ArrayList<>();
@@ -69,9 +80,6 @@ public Pair<String, Map<String, Object>> buildQueryFromSearch(FareZoneSearch sea
             parameters.put("zoneTopology",search.getZoneTopologyEnumeration().name());
         }
 
-        operators.add("and");
-        wheres.add("f.version = (select max(fv.version) from fare_zone fv where fv.netex_id = f.netex_id and (fv.to_date is null or fv.to_date > now()) and (fv.from_date is null or fv.from_date < now()))");
-
         searchHelper.addWheres(queryString, wheres, operators);
         searchHelper.addOrderByStatements(queryString, orderByStatements);
         final String generatedSql = searchHelper.format(queryString.toString());

src/main/resources/db/migration/V61__add_fare_zone_netex_id_index.sql

@@ -0,0 +1,3 @@
+CREATE INDEX idx_fare_zone_netex_id ON fare_zone (netex_id);
+CREATE INDEX idx_fare_zone_netex_id_version ON fare_zone (netex_id, version);
+CREATE INDEX idx_fare_zone_validity ON fare_zone (netex_id, version, from_date, to_date);

src/test/java/org/rutebanken/tiamat/repository/FareZoneRepositoryImplTest.java

@@ -141,6 +141,35 @@ public void findFareZonesByIdPrefix() throws Exception {
                 .containsOnly(fareZone2V.getNetexId());
     }
 
+    @Test
+    public void findFareZonesReturnsOnlyCurrentVersionWhenMultipleVersionsExist() {
+        String netexId = "RUT:FareZone:MultiVersion";
+        Instant past = Instant.now().minusSeconds(3600);
+
+        FareZone v1 = new FareZone();
+        v1.setNetexId(netexId);
+        v1.setVersion(1L);
+        v1.setName(new EmbeddableMultilingualString("Old"));
+        v1.setValidBetween(new ValidBetween(past, past.plusSeconds(60)));
+        fareZoneRepository.save(v1);
+
+        FareZone v2 = new FareZone();
+        v2.setNetexId(netexId);
+        v2.setVersion(2L);
+        v2.setName(new EmbeddableMultilingualString("Current"));
+        v2.setValidBetween(new ValidBetween(past, null));
+        fareZoneRepository.save(v2);
+
+        FareZoneSearch search = FareZoneSearch.newFareZoneSearchBuilder().build();
+        List<FareZone> result = fareZoneRepository.findFareZones(search);
+
+        assertThat(result)
+                .filteredOn(fz -> netexId.equals(fz.getNetexId()))
+                .hasSize(1)
+                .extracting(FareZone::getVersion)
+                .containsOnly(2L);
+    }
+
     @Test
     public void getFareZonesFromStopPlaceIds() throws Exception {