Optimize REPLACE for index-only items

1) We re-added cascading on SAVE/UPDATE - it seems that it can be
   safely used
2) When replacing, we simply add values to the collection instead of
   persisting them manually. It looks like the persist, although
   produces no SQL command, is particularly slow because of Hibernate
   processing.
3) We do not apply item-only modifications to main prism object
   (there's no point in doing so).

repo/repo-sql-impl/src/main/java/com/evolveum/midpoint/repo/sql/data/common/RObject.java

@@ -74,17 +74,6 @@
 
 /**
  * @author lazyman
- *
- * TO BE RESEARCHED FURTHER:
- *
- * Note on cascading into extension values sets: At one time it looked like that if we wanted to avoid fetching all values when doing DELETE,
- * we had to restrict cascading of SAVE/UPDATE operation to them. Otherwise it was not sufficient to remove respective extension
- * values from DB, because it was necessary to remove them also from the respective collection. And this incured SELECT operation
- * on all collection members.
- *
- * (Now it seems that this works even when cascade = ALL. That's why it needs to be researched a bit more.)
- *
- * For all related places, see [SAVE-CASCADE] mark.
  */
 @NamedQueries({
         @NamedQuery(name = "get.focusPhoto", query = "select p.photo from RFocusPhoto p where p.ownerOid = :oid"),
@@ -389,43 +378,48 @@ public XMLGregorianCalendar getModifyTimestamp() {
 
     @NotQueryable
     @OneToMany(fetch = FetchType.LAZY, mappedBy = "owner", orphanRemoval = true)
-    @Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE - see [SAVE-CASCADE]
+    //@Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE
+    @Cascade({ ALL} )
     public Collection<ROExtLong> getLongs() {
         return longs;
     }
 
     @NotQueryable
     @OneToMany(fetch = FetchType.LAZY, mappedBy = "owner", orphanRemoval = true)
-    @Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE - see [SAVE-CASCADE]
+    //@Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE
+    @Cascade({ ALL} )
     public Collection<ROExtBoolean> getBooleans() {
         return booleans;
     }
 
     @NotQueryable
     @OneToMany(fetch = FetchType.LAZY, mappedBy = "owner", orphanRemoval = true)
-    @Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE - see [SAVE-CASCADE]
-    //@Cascade({ ALL} )
+    //@Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE
+    @Cascade({ ALL} )
     public Collection<ROExtString> getStrings() {
         return strings;
     }
 
     @NotQueryable
     @OneToMany(fetch = FetchType.LAZY, mappedBy = "owner", orphanRemoval = true)
-    @Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE - see [SAVE-CASCADE]
+    //@Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE
+    @Cascade({ ALL} )
     public Collection<ROExtDate> getDates() {
         return dates;
     }
 
     @NotQueryable
     @OneToMany(fetch = FetchType.LAZY, mappedBy = "owner", orphanRemoval = true)
-    @Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE - see [SAVE-CASCADE]
+    //@Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE
+    @Cascade({ ALL} )
     public Collection<ROExtReference> getReferences() {
         return references;
     }
 
     @NotQueryable
     @OneToMany(fetch = FetchType.LAZY, mappedBy = "owner", orphanRemoval = true)
-    @Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE - see [SAVE-CASCADE]
+    //@Cascade({ PERSIST, MERGE, REMOVE, REFRESH, DELETE, REPLICATE, LOCK, DETACH })      // not SAVE_UPDATE
+    @Cascade({ ALL} )
     public Collection<ROExtPolyString> getPolys() {
         return polys;
     }

repo/repo-sql-impl/src/main/java/com/evolveum/midpoint/repo/sql/data/common/any/RAssignmentExtension.java

@@ -42,9 +42,6 @@
 
 /**
  * @author lazyman
- *
- * Note: We do cascade = ALL, unlike in RObject class. We do not try to eliminate "get all ext values" queries like in RObject - yet.
- * See [SAVE-CASCADE]
  */
 @Ignore
 @Entity

repo/repo-sql-impl/src/main/java/com/evolveum/midpoint/repo/sql/helpers/ObjectDeltaUpdater.java

@@ -353,7 +353,14 @@ private <T extends ObjectType> void handleObjectCommonAttributes(Class<T> type,
         object.setVersion(version);
 
         // apply modifications, ids' for new containers already filled in delta values
-        ItemDeltaCollectionsUtil.applyTo(modifications, prismObject);
+        for (ItemDelta<?, ?> modification : modifications) {
+            if (modification.getDefinition() == null || !modification.getDefinition().isIndexOnly()) {
+                modification.applyTo(prismObject);
+            } else {
+                // There's no point in applying modifications to index-only items; they are not serialized.
+                // (Presumably they are not indexed as well.)
+            }
+        }
 
         handleObjectTextInfoChanges(type, modifications, prismObject, object);
 
@@ -552,11 +559,25 @@ private static <T> void markNewValuesTransientAndAddToExistingNoFetch(Collection
             if (!exists) {
                 //noinspection unchecked
                 ((Collection) dbCollection).add(rValue);
-                ctx.session.persist(rValue);            // save is not cascaded to extension values any more [SAVE-CASCADE]
+                ctx.session.persist(rValue);            // it looks that in this way we avoid SQL SELECT (at the cost of .persist that can be sometimes more costly)
             }
         }
     }
 
+    /**
+     * Similar to DeltaUpdaterUtils.markNewValuesTransientAndAddToExisting but simpler.
+     *
+     * We rely on the fact that SAVE/UPDATE is now cascaded to extension items.
+     */
+    private static <T> void markNewValuesTransientAndAddToExistingNoFetchNoPersist(Collection<? extends RAnyValue<?>> dbCollection,
+            Collection<PrismEntityPair<RAnyValue<?>>> newValues, Context ctx) {
+        for (PrismEntityPair<RAnyValue<?>> item : newValues) {
+            RAnyValue<?> rValue = item.getRepository();
+            //noinspection unchecked
+            ((Collection) dbCollection).add(rValue);
+        }
+    }
+
     private void deleteExtensionValues(Collection<? extends RAnyValue<?>> dbCollection,
             Collection<PrismEntityPair<RAnyValue<?>>> pairsFromDelta, Context ctx) {
         if (pairsFromDelta.isEmpty()) {
@@ -669,7 +690,7 @@ private void replaceExtensionValues(RObjectExtensionType objectExtensionType,
         }
 
         deleteFromCollectionAndDb(dbCollection, rValuesToDelete, ctx.session);
-        markNewValuesTransientAndAddToExistingNoFetch(dbCollection, pairsToAdd, ctx);
+        markNewValuesTransientAndAddToExistingNoFetchNoPersist(dbCollection, pairsToAdd, ctx);
     }
 
     private void deleteFromCollectionAndDb(Collection<? extends RAnyValue<?>> dbCollection,

repo/repo-sql-impl/src/main/java/com/evolveum/midpoint/repo/sql/helpers/ObjectUpdater.java

@@ -305,9 +305,6 @@ private <T extends ObjectType> String nonOverwriteAddObjectAttempt(PrismObject<T
         updateFullObject(rObject, object);
 
         LOGGER.trace("Saving object (non overwrite).");
-        // By using persist() instead of save we cascade this operation to object+assignment extension values.
-        // (Save is intentionally not cascaded, because we need to add+delete these values manually.)
-        // See [SAVE-CASCADE].
         session.persist(rObject);
         lookupTableHelper.addLookupTableRows(session, rObject, false);
         caseHelper.addCertificationCampaignCases(session, rObject, false);

repo/repo-sql-impl/src/main/java/com/evolveum/midpoint/repo/sql/helpers/modify/DeltaUpdaterUtils.java

@@ -226,18 +226,17 @@ private static void clearExtensionCollection(Collection<? extends RAExtBase<?>>
         while (iterator.hasNext()) {
             RAExtBase dbValue = iterator.next();
             // we cannot filter on assignmentExtensionType because it is not present in database (yet)
-            session.delete(dbValue);    // see [SAVE-CASCADE]
             iterator.remove();
         }
     }
 
     private static void clearExtensionCollection(Collection<? extends ROExtBase<?>> dbCollection, RObjectExtensionType typeToDelete,
             Session session) {
         Iterator<? extends ROExtBase> iterator = dbCollection.iterator();
+        //noinspection Java8CollectionRemoveIf
         while (iterator.hasNext()) {
             ROExtBase dbValue = iterator.next();
             if (typeToDelete.equals(dbValue.getOwnerType())) {
-                session.delete(dbValue);    // see [SAVE-CASCADE]
                 iterator.remove();
             }
         }