Do not fetch the entire entity if only the id is needed.

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/migration/CaseInstanceMigrationManagerImpl.java

@@ -105,11 +105,11 @@ public CaseInstanceMigrationValidationResult validateMigrateCaseInstancesOfCaseD
                 CmmnModel newModel = CaseDefinitionUtil.getCmmnModel(caseDefinition.getId());
 
                 CaseInstanceEntityManager caseInstanceEntityManager = cmmnEngineConfiguration.getCaseInstanceEntityManager();
-                List<CaseInstance> caseInstances = caseInstanceEntityManager.findByCriteria(
+                List<String> caseInstanceIds = caseInstanceEntityManager.findIdsByCriteria(
                         new CaseInstanceQueryImpl(commandContext, cmmnEngineConfiguration).caseDefinitionId(caseDefinitionId));
 
-                for (CaseInstance caseInstance : caseInstances) {
-                    doValidateCaseInstanceMigration(caseInstance.getId(), newModel, document, validationResult, commandContext);
+                for (String caseInstanceId : caseInstanceIds) {
+                    doValidateCaseInstanceMigration(caseInstanceId, newModel, document, validationResult, commandContext);
                 }
             }
         }
@@ -497,9 +497,10 @@ public Batch batchMigrateHistoricCaseInstancesOfCaseDefinition(String caseDefini
         CaseDefinition caseDefinition = resolveCaseDefinition(document, commandContext);
 
         CmmnEngineConfiguration engineConfiguration = CommandContextUtil.getCmmnEngineConfiguration();
-        HistoricCaseInstanceQueryImpl historicCaseInstanceQuery = new HistoricCaseInstanceQueryImpl(commandContext, cmmnEngineConfiguration).caseDefinitionId(caseDefinitionId).finished();
-        List<HistoricCaseInstance> historicCaseInstances = engineConfiguration.getHistoricCaseInstanceEntityManager()
-                .findByCriteria(historicCaseInstanceQuery);
+        HistoricCaseInstanceQueryImpl historicCaseInstanceQuery = new HistoricCaseInstanceQueryImpl(commandContext, cmmnEngineConfiguration).caseDefinitionId(
+                caseDefinitionId).finished();
+        List<String> historicCaseInstanceIds = engineConfiguration.getHistoricCaseInstanceEntityManager()
+                .findIdsByCriteria(historicCaseInstanceQuery);
 
         BatchService batchService = engineConfiguration.getBatchServiceConfiguration().getBatchService();
         Batch batch = batchService.createBatchBuilder().batchType(Batch.CASE_MIGRATION_TYPE)
@@ -510,20 +511,20 @@ public Batch batchMigrateHistoricCaseInstancesOfCaseDefinition(String caseDefini
                 .create();
 
         JobService jobService = engineConfiguration.getJobServiceConfiguration().getJobService();
-        for (HistoricCaseInstance historicCaseInstance : historicCaseInstances) {
+        for (String historicCaseInstanceId : historicCaseInstanceIds) {
             BatchPart batchPart = batchService.createBatchPart(batch, CaseInstanceBatchMigrationResult.STATUS_WAITING,
-                    historicCaseInstance.getId(), null, ScopeTypes.CMMN);
+                    historicCaseInstanceId, null, ScopeTypes.CMMN);
 
             JobEntity job = jobService.createJob();
             job.setJobHandlerType(HistoricCaseInstanceMigrationJobHandler.TYPE);
-            job.setScopeId(historicCaseInstance.getId());
+            job.setScopeId(historicCaseInstanceId);
             job.setScopeType(ScopeTypes.CMMN);
             job.setJobHandlerConfiguration(HistoricCaseInstanceMigrationJobHandler.getHandlerCfgForBatchPartId(batchPart.getId()));
             jobService.createAsyncJob(job, false);
             jobService.scheduleAsyncJob(job);
         }
 
-        if (!historicCaseInstances.isEmpty()) {
+        if (!historicCaseInstanceIds.isEmpty()) {
             TimerJobService timerJobService = engineConfiguration.getJobServiceConfiguration().getTimerJobService();
             TimerJobEntity timerJob = timerJobService.createTimerJob();
             timerJob.setJobType(JobEntity.JOB_TYPE_TIMER);

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/CaseDefinitionEntityManagerImpl.java

@@ -15,11 +15,9 @@
 
 import java.util.List;
 
-import org.flowable.cmmn.api.history.HistoricCaseInstance;
 import org.flowable.cmmn.api.history.HistoricMilestoneInstance;
 import org.flowable.cmmn.api.repository.CaseDefinition;
 import org.flowable.cmmn.api.repository.CaseDefinitionQuery;
-import org.flowable.cmmn.api.runtime.CaseInstance;
 import org.flowable.cmmn.engine.CmmnEngineConfiguration;
 import org.flowable.cmmn.engine.impl.history.CmmnHistoryHelper;
 import org.flowable.cmmn.engine.impl.history.HistoricCaseInstanceQueryImpl;
@@ -90,22 +88,23 @@ public CaseDefinition findCaseDefinitionByKeyAndVersionAndTenantId(String caseDe
 
     @Override
     public void deleteCaseDefinitionAndRelatedData(String caseDefinitionId, boolean cascadeHistory) {
-        
+
         // Case instances
         CaseInstanceEntityManager caseInstanceEntityManager = getCaseInstanceEntityManager();
         CommandContext commandContext = Context.getCommandContext();
-        List<CaseInstance> caseInstances = caseInstanceEntityManager.findByCriteria(
+        List<String> caseInstanceIds = caseInstanceEntityManager.findIdsByCriteria(
                 new CaseInstanceQueryImpl(commandContext, engineConfiguration).caseDefinitionId(caseDefinitionId));
-        for (CaseInstance caseInstance : caseInstances) {
-            caseInstanceEntityManager.delete(caseInstance.getId(), true, null);
+        for (String caseInstanceId : caseInstanceIds) {
+            caseInstanceEntityManager.delete(caseInstanceId, true, null);
         }
-        
+
         if (cascadeHistory) {
-            engineConfiguration.getTaskServiceConfiguration().getHistoricTaskService().deleteHistoricTaskLogEntriesForScopeDefinition(ScopeTypes.CMMN, caseDefinitionId);
+            engineConfiguration.getTaskServiceConfiguration().getHistoricTaskService()
+                    .deleteHistoricTaskLogEntriesForScopeDefinition(ScopeTypes.CMMN, caseDefinitionId);
 
             HistoricIdentityLinkEntityManager historicIdentityLinkEntityManager = getHistoricIdentityLinkEntityManager();
             historicIdentityLinkEntityManager.deleteHistoricIdentityLinksByScopeDefinitionIdAndScopeType(caseDefinitionId, ScopeTypes.CMMN);
-            
+
             // Historic milestone
             HistoricMilestoneInstanceEntityManager historicMilestoneInstanceEntityManager = getHistoricMilestoneInstanceEntityManager();
             List<HistoricMilestoneInstance> historicMilestoneInstances = historicMilestoneInstanceEntityManager
@@ -117,7 +116,7 @@ public void deleteCaseDefinitionAndRelatedData(String caseDefinitionId, boolean
             // Historic tasks
             HistoricTaskInstanceEntityManager historicTaskInstanceEntityManager = getHistoricTaskInstanceEntityManager();
             List<HistoricTaskInstance> historicTaskInstances = historicTaskInstanceEntityManager
-                    .findHistoricTaskInstancesByQueryCriteria(new HistoricTaskInstanceQueryImpl().scopeDefinitionId(caseDefinitionId).scopeType(ScopeTypes.CMMN)); 
+                    .findHistoricTaskInstancesByQueryCriteria(new HistoricTaskInstanceQueryImpl().scopeDefinitionId(caseDefinitionId).scopeType(ScopeTypes.CMMN));
             for (HistoricTaskInstance historicTaskInstance : historicTaskInstances) {
                 TaskHelper.deleteHistoricTask(historicTaskInstance.getId(), engineConfiguration);
             }
@@ -128,10 +127,10 @@ public void deleteCaseDefinitionAndRelatedData(String caseDefinitionId, boolean
                     .forEach(p -> historicPlanItemInstanceEntityManager.delete(p.getId()));
 
             HistoricCaseInstanceEntityManager historicCaseInstanceEntityManager = getHistoricCaseInstanceEntityManager();
-            List<HistoricCaseInstance> historicCaseInstanceEntities = historicCaseInstanceEntityManager
-                    .findByCriteria(new HistoricCaseInstanceQueryImpl().caseDefinitionId(caseDefinitionId));
-            for (HistoricCaseInstance historicCaseInstanceEntity : historicCaseInstanceEntities) {
-                CmmnHistoryHelper.deleteHistoricCaseInstance(engineConfiguration, historicCaseInstanceEntity.getId());
+            List<String> historicCaseInstanceIds = historicCaseInstanceEntityManager
+                    .findIdsByCriteria(new HistoricCaseInstanceQueryImpl().caseDefinitionId(caseDefinitionId));
+            for (String historicCaseInstanceId : historicCaseInstanceIds) {
+                CmmnHistoryHelper.deleteHistoricCaseInstance(engineConfiguration, historicCaseInstanceId);
             }
         }
 

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/CaseInstanceEntityManager.java

@@ -35,14 +35,16 @@ public interface CaseInstanceEntityManager extends EntityManager<CaseInstanceEnt
 
     List<CaseInstance> findByCriteria(CaseInstanceQuery query);
 
+    List<String> findIdsByCriteria(CaseInstanceQuery query);
+
     List<CaseInstance> findWithVariablesByCriteria(CaseInstanceQuery query);
 
     long countByCriteria(CaseInstanceQuery query);
 
     void delete(String caseInstanceId, boolean cascade, String deleteReason);
-    
+
     void updateCaseInstanceBusinessKey(CaseInstanceEntity caseInstanceEntity, String businessKey);
-    
+
     void updateCaseInstanceBusinessStatus(CaseInstanceEntity caseInstanceEntity, String businessStatus);
 
     void updateLockTime(String caseInstanceId, String lockOwner, Date lockTime);

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/CaseInstanceEntityManagerImpl.java

@@ -84,6 +84,11 @@ public List<CaseInstance> findByCriteria(CaseInstanceQuery query) {
         return dataManager.findByCriteria((CaseInstanceQueryImpl) query);
     }
 
+    @Override
+    public List<String> findIdsByCriteria(CaseInstanceQuery query) {
+        return dataManager.findIdsByCriteria((CaseInstanceQueryImpl) query);
+    }
+
     @Override
     public List<CaseInstance> findWithVariablesByCriteria(CaseInstanceQuery query) {
         return dataManager.findWithVariablesByCriteria((CaseInstanceQueryImpl) query);

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/HistoricCaseInstanceEntityManager.java

@@ -27,20 +27,22 @@
 public interface HistoricCaseInstanceEntityManager extends EntityManager<HistoricCaseInstanceEntity> {
 
     HistoricCaseInstanceEntity create(CaseInstance caseInstance);
-    
+
     HistoricCaseInstanceQuery createHistoricCaseInstanceQuery();
-    
+
     List<HistoricCaseInstanceEntity> findHistoricCaseInstancesByCaseDefinitionId(String caseDefinitionId);
-    
+
     List<String> findHistoricCaseInstanceIdsByParentIds(Collection<String> caseInstanceIds);
-    
+
     List<HistoricCaseInstance> findByCriteria(HistoricCaseInstanceQuery query);
 
+    List<String> findIdsByCriteria(HistoricCaseInstanceQuery query);
+
     List<HistoricCaseInstance> findWithVariablesByQueryCriteria(HistoricCaseInstanceQuery query);
 
     long countByCriteria(HistoricCaseInstanceQuery query);
-    
+
     void deleteHistoricCaseInstances(HistoricCaseInstanceQueryImpl historicCaseInstanceQuery);
-    
+
     void bulkDeleteHistoricCaseInstances(Collection<String> caseInstanceIds);
 }

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/HistoricCaseInstanceEntityManagerImpl.java

@@ -60,6 +60,11 @@ public List<HistoricCaseInstance> findByCriteria(HistoricCaseInstanceQuery query
         return dataManager.findByCriteria((HistoricCaseInstanceQueryImpl) query);
     }
 
+    @Override
+    public List<String> findIdsByCriteria(HistoricCaseInstanceQuery query) {
+        return dataManager.findIdsByCriteria((HistoricCaseInstanceQueryImpl) query);
+    }
+
     @Override
     @SuppressWarnings("unchecked")
     public List<HistoricCaseInstance> findWithVariablesByQueryCriteria(HistoricCaseInstanceQuery query) {

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/data/CaseInstanceDataManager.java

@@ -36,6 +36,8 @@ public interface CaseInstanceDataManager extends DataManager<CaseInstanceEntity>
 
     List<CaseInstance> findByCriteria(CaseInstanceQueryImpl query);
 
+    List<String> findIdsByCriteria(CaseInstanceQueryImpl query);
+
     List<CaseInstance> findWithVariablesByCriteria(CaseInstanceQueryImpl query);
 
     long countByCriteria(CaseInstanceQueryImpl query);

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/data/HistoricCaseInstanceDataManager.java

@@ -27,20 +27,22 @@
 public interface HistoricCaseInstanceDataManager extends DataManager<HistoricCaseInstanceEntity> {
 
     HistoricCaseInstanceEntity create(CaseInstance caseInstance);
-    
+
     List<HistoricCaseInstanceEntity> findHistoricCaseInstancesByCaseDefinitionId(String caseDefinitionId);
-    
+
     List<String> findHistoricCaseInstanceIdsByParentIds(Collection<String> caseInstanceIds);
-    
+
     List<HistoricCaseInstance> findByCriteria(HistoricCaseInstanceQueryImpl query);
-
+
+    List<String> findIdsByCriteria(HistoricCaseInstanceQueryImpl query);
+
     long countByCriteria(HistoricCaseInstanceQueryImpl query);
 
     List<HistoricCaseInstance> findWithVariablesByQueryCriteria(HistoricCaseInstanceQueryImpl historicCaseInstanceQuery);
 
     void deleteByCaseDefinitionId(String caseDefinitionId);
-    
+
     void deleteHistoricCaseInstances(HistoricCaseInstanceQueryImpl historicCaseInstanceQuery);
-    
+
     void bulkDeleteHistoricCaseInstances(Collection<String> caseInstanceIds);
 }

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/data/impl/MybatisCaseInstanceDataManagerImpl.java

@@ -172,6 +172,15 @@ public List<CaseInstance> findByCriteria(CaseInstanceQueryImpl query) {
         return getDbSqlSession().selectListNoCacheLoadAndStore("selectCaseInstancesByQueryCriteria", query, getManagedEntityClass());
     }
 
+    @Override
+    @SuppressWarnings("unchecked")
+    public List<String> findIdsByCriteria(CaseInstanceQueryImpl query) {
+        // Not going through cache as the case instance should always be loaded with all related plan item instances
+        // when not doing a query call
+        setSafeInValueLists(query);
+        return getDbSqlSession().selectListNoCacheLoadAndStore("selectCaseInstanceIdsByQueryCriteria", query, getManagedEntityClass());
+    }
+
     @SuppressWarnings("unchecked")
     @Override
     public List<CaseInstance> findWithVariablesByCriteria(CaseInstanceQueryImpl query) {

modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/persistence/entity/data/impl/MybatisHistoricCaseInstanceDataManagerImpl.java

@@ -69,6 +69,13 @@ public List<HistoricCaseInstance> findByCriteria(HistoricCaseInstanceQueryImpl q
         return getDbSqlSession().selectList("selectHistoricCaseInstancesByQueryCriteria", query, getManagedEntityClass());
     }
 
+    @Override
+    @SuppressWarnings("unchecked")
+    public List<String> findIdsByCriteria(HistoricCaseInstanceQueryImpl query) {
+        setSafeInValueLists(query);
+        return getDbSqlSession().selectList("selectHistoricCaseInstanceIdsByQueryCriteria", query, getManagedEntityClass());
+    }
+
     @Override
     public long countByCriteria(HistoricCaseInstanceQueryImpl query) {
         setSafeInValueLists(query);

modules/flowable-cmmn-engine/src/main/resources/org/flowable/cmmn/db/mapping/entity/CaseInstance.xml

@@ -288,14 +288,26 @@
     <select id="selectCaseInstancesByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.runtime.CaseInstanceQueryImpl" resultMap="caseInstanceResultMap">
         <if test="needsPaging">${limitBefore}</if>
         select RES.* <if test="needsPaging">${limitBetween}</if>,
-            CASE_DEF.KEY_ as CaseDefinitionKey,
-            CASE_DEF.NAME_ as CaseDefinitionName,
-            CASE_DEF.VERSION_ as CaseDefinitionVersion,
-            CASE_DEF.DEPLOYMENT_ID_ as CaseDefinitionDeploymentId
+        CASE_DEF.KEY_ as CaseDefinitionKey,
+        CASE_DEF.NAME_ as CaseDefinitionName,
+        CASE_DEF.VERSION_ as CaseDefinitionVersion,
+        CASE_DEF.DEPLOYMENT_ID_ as CaseDefinitionDeploymentId
         from ${prefix}ACT_CMMN_RU_CASE_INST RES
         <!-- Doing an inner join on the definition table is OK, since it is a 1:1 relationship -->
         inner join ${prefix}ACT_CMMN_CASEDEF CASE_DEF on RES.CASE_DEF_ID_ = CASE_DEF.ID_
-        <include refid="commonSelectCaseInstancesByQueryCriteriaSql" />
+        <include refid="commonSelectCaseInstancesByQueryCriteriaSql"/>
+        ${orderBy}
+        <if test="needsPaging">${limitAfter}</if>
+    </select>
+
+    <select id="selectCaseInstanceIdsByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.runtime.CaseInstanceQueryImpl" resultType="string">
+        <if test="needsPaging">${limitBefore}</if>
+        select RES.ID_
+        <if test="needsPaging">${limitBetween}</if>
+        from ${prefix}ACT_CMMN_RU_CASE_INST RES
+        <!-- Doing an inner join on the definition table is OK, since it is a 1:1 relationship -->
+        inner join ${prefix}ACT_CMMN_CASEDEF CASE_DEF on RES.CASE_DEF_ID_ = CASE_DEF.ID_
+        <include refid="commonSelectCaseInstancesByQueryCriteriaSql"/>
         ${orderBy}
         <if test="needsPaging">${limitAfter}</if>
     </select>
@@ -304,7 +316,7 @@
         select count(distinct RES.ID_) from ${prefix}ACT_CMMN_RU_CASE_INST RES
         <!-- Doing an inner join on the definition table is OK, since it is a 1:1 relationship -->
         inner join ${prefix}ACT_CMMN_CASEDEF CASE_DEF on RES.CASE_DEF_ID_ = CASE_DEF.ID_
-        <include refid="commonSelectCaseInstancesByQueryCriteriaSql" />
+        <include refid="commonSelectCaseInstancesByQueryCriteriaSql"/>
     </select>
 
     <select id="selectCaseInstanceWithVariablesByQueryCriteria"

modules/flowable-cmmn-engine/src/main/resources/org/flowable/cmmn/db/mapping/entity/HistoricCaseInstance.xml

@@ -232,21 +232,33 @@
         </foreach>
     </select>
 
-    <select id="selectHistoricCaseInstancesByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.history.HistoricCaseInstanceQueryImpl" resultMap="historicCaseInstanceResultMap">
+    <select id="selectHistoricCaseInstancesByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.history.HistoricCaseInstanceQueryImpl"
+            resultMap="historicCaseInstanceResultMap">
         <if test="needsPaging">${limitBefore}</if>
         select RES.* <if test="needsPaging">${limitBetween}</if>,
-            CASE_DEF.KEY_ as CaseDefinitionKey,
-            CASE_DEF.NAME_ as CaseDefinitionName,
-            CASE_DEF.VERSION_ as CaseDefinitionVersion,
-            CASE_DEF.DEPLOYMENT_ID_ as CaseDefinitionDeploymentId
-        <include refid="selectHistoricCaseInstancesByQueryCriteriaSql" />
+        CASE_DEF.KEY_ as CaseDefinitionKey,
+        CASE_DEF.NAME_ as CaseDefinitionName,
+        CASE_DEF.VERSION_ as CaseDefinitionVersion,
+        CASE_DEF.DEPLOYMENT_ID_ as CaseDefinitionDeploymentId
+        <include refid="selectHistoricCaseInstancesByQueryCriteriaSql"/>
+        ${orderBy}
+        <if test="needsPaging">${limitAfter}</if>
+    </select>
+
+    <select id="selectHistoricCaseInstanceIdsByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.history.HistoricCaseInstanceQueryImpl"
+            resultType="string">
+        <if test="needsPaging">${limitBefore}</if>
+        select RES.ID_
+        <if test="needsPaging">${limitBetween}</if>
+        <include refid="selectHistoricCaseInstancesByQueryCriteriaSql"/>
         ${orderBy}
         <if test="needsPaging">${limitAfter}</if>
     </select>
 
-    <select id="selectHistoricCaseInstanceCountByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.history.HistoricCaseInstanceQueryImpl" resultType="long">
+    <select id="selectHistoricCaseInstanceCountByQueryCriteria" parameterType="org.flowable.cmmn.engine.impl.history.HistoricCaseInstanceQueryImpl"
+            resultType="long">
         select count(distinct RES.ID_)
-        <include refid="selectHistoricCaseInstancesByQueryCriteriaSql" />
+        <include refid="selectHistoricCaseInstancesByQueryCriteriaSql"/>
     </select>
 
     <select id="selectHistoricCaseInstancesWithVariablesByQueryCriteria"