Reduce DB roundtrips for revincludes (#1937)

* Reduce DB roundtrips for revincludes

* Add changelog

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/5_1_0/1937-reduce-revinclude-db-roundtrips.yaml

@@ -0,0 +1,6 @@
+---
+type: perf
+issue: 1937
+title: Due to an inefficient SQL statement when performing searches with large numbers of _revincludes where the resources
+   have tags, a large number of database roundtrips were produced when searching. This has been streamlined, greatly improving
+   the response times for some searches.

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/data/IResourceTagDao.java

@@ -32,7 +32,7 @@ import ca.uhn.fhir.jpa.model.entity.ResourceTag;
 public interface IResourceTagDao extends JpaRepository<ResourceTag, Long> {
 	@Query("" + 
 			   "SELECT t FROM ResourceTag t " + 
-			   "INNER JOIN TagDefinition td ON (td.myId = t.myTagId) " + 
+			   "INNER JOIN FETCH t.myTag td " +
 			   "WHERE t.myResourceId in (:pids)")
 	Collection<ResourceTag> findByResourceIds(@Param("pids") Collection<Long> pids);
 

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/dao/r4/FhirResourceDaoR4QueryCountTest.java

@@ -4,11 +4,13 @@ import ca.uhn.fhir.jpa.api.config.DaoConfig;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 import ca.uhn.fhir.jpa.util.SqlQuery;
 import ca.uhn.fhir.jpa.util.TestUtil;
+import ca.uhn.fhir.rest.api.SortSpec;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.param.ReferenceParam;
 import org.apache.commons.lang3.StringUtils;
 import org.hl7.fhir.instance.model.api.IIdType;
 import org.hl7.fhir.r4.model.Bundle;
+import org.hl7.fhir.r4.model.CareTeam;
 import org.hl7.fhir.r4.model.CodeSystem;
 import org.hl7.fhir.r4.model.DateTimeType;
 import org.hl7.fhir.r4.model.IdType;
@@ -538,6 +540,53 @@ public class FhirResourceDaoR4QueryCountTest extends BaseJpaR4Test {
 	}
 
 
+	@Test
+	public void testSearchOnReverseInclude() {
+		Patient patient = new Patient();
+		patient.getMeta().addTag("http://system", "value1", "display");
+		patient.setId("P1");
+		patient.getNameFirstRep().setFamily("FAM1");
+		myPatientDao.update(patient);
+
+		patient = new Patient();
+		patient.setId("P2");
+		patient.getMeta().addTag("http://system", "value1", "display");
+		patient.getNameFirstRep().setFamily("FAM2");
+		myPatientDao.update(patient);
+
+		for (int i = 0; i < 3; i++) {
+			CareTeam ct = new CareTeam();
+			ct.setId("CT1-" + i);
+			ct.getMeta().addTag("http://system", "value11", "display");
+			ct.getSubject().setReference("Patient/P1");
+			myCareTeamDao.update(ct);
+
+			ct = new CareTeam();
+			ct.setId("CT2-" + i);
+			ct.getMeta().addTag("http://system", "value22", "display");
+			ct.getSubject().setReference("Patient/P2");
+			myCareTeamDao.update(ct);
+		}
+
+		SearchParameterMap map = SearchParameterMap
+			.newSynchronous()
+			.addRevInclude(CareTeam.INCLUDE_SUBJECT)
+			.setSort(new SortSpec(Patient.SP_NAME));
+
+		myCaptureQueriesListener.clear();
+		IBundleProvider outcome = myPatientDao.search(map);
+		assertThat(toUnqualifiedVersionlessIdValues(outcome), containsInAnyOrder(
+			"Patient/P1", "CareTeam/CT1-0", "CareTeam/CT1-1","CareTeam/CT1-2",
+			"Patient/P2", "CareTeam/CT2-0", "CareTeam/CT2-1","CareTeam/CT2-2"
+		));
+
+		myCaptureQueriesListener.logSelectQueriesForCurrentThread();
+		assertEquals(4, myCaptureQueriesListener.getSelectQueriesForCurrentThread().size());
+		assertEquals(0, myCaptureQueriesListener.getInsertQueriesForCurrentThread().size());
+		assertEquals(0, myCaptureQueriesListener.getUpdateQueriesForCurrentThread().size());
+		assertEquals(0, myCaptureQueriesListener.getDeleteQueriesForCurrentThread().size());
+	}
+
 	@Test
 	public void testTransactionWithMultipleReferences() {
 		Bundle input = new Bundle();

hapi-fhir-jpaserver-model/src/main/java/ca/uhn/fhir/jpa/model/entity/ResourceTag.java

@@ -42,7 +42,7 @@ public class ResourceTag extends BaseTag {
 	@Column(name = "PID")
 	private Long myId;
 
-	@ManyToOne(cascade = {})
+	@ManyToOne(cascade = {}, fetch = FetchType.LAZY)
 	@JoinColumn(name = "RES_ID", referencedColumnName = "RES_ID", foreignKey = @ForeignKey(name = "FK_RESTAG_RESOURCE"))
 	private ResourceTable myResource;
 

hapi-fhir-jpaserver-searchparam/src/main/java/ca/uhn/fhir/jpa/searchparam/SearchParameterMap.java

@@ -159,8 +159,9 @@ public class SearchParameterMap implements Serializable {
 		}
 	}
 
-	public void addRevInclude(Include theInclude) {
+	public SearchParameterMap addRevInclude(Include theInclude) {
 		getRevIncludes().add(theInclude);
+		return this;
 	}
 
 	private void addUrlIncludeParams(StringBuilder b, String paramName, Set<Include> theList) {
@@ -268,8 +269,9 @@ public class SearchParameterMap implements Serializable {
 		return mySort;
 	}
 
-	public void setSort(SortSpec theSort) {
+	public SearchParameterMap setSort(SortSpec theSort) {
 		mySort = theSort;
+		return this;
 	}
 
 	/**