#1795 - Refactor bind padding for Id IN expressions (based on internal multiValueSupport and simple id)

src/main/java/io/ebean/event/BeanQueryRequest.java

@@ -24,6 +24,11 @@ public interface BeanQueryRequest<T> {
    */
   Query<T> getQuery();
 
+  /**
+   * Return true if an Id IN expression should have the bind parameters padded.
+   */
+  boolean isPadInExpression();
+
   /**
    * Return true if multi-value binding using Array or Table Values is supported.
    */

src/main/java/io/ebeaninternal/api/LoadBeanRequest.java

@@ -4,8 +4,6 @@ import io.ebean.bean.EntityBean;
 import io.ebean.bean.EntityBeanIntercept;
 import io.ebeaninternal.server.core.OrmQueryRequest;
 import io.ebeaninternal.server.deploy.BeanDescriptor;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -17,8 +15,6 @@ import java.util.Set;
  */
 public class LoadBeanRequest extends LoadRequest {
 
-  private static final Logger logger = LoggerFactory.getLogger(LoadBeanRequest.class);
-
   private final List<EntityBeanIntercept> batch;
 
   private final LoadBeanBuffer loadBuffer;
@@ -56,7 +52,7 @@ public class LoadBeanRequest extends LoadRequest {
     return loadBuffer.getBeanDescriptor().getBeanType();
   }
 
-  public boolean isLoadCache() {
+  private boolean isLoadCache() {
     return loadCache;
   }
 
@@ -75,17 +71,10 @@ public class LoadBeanRequest extends LoadRequest {
   /**
    * Return the load context.
    */
-  public LoadBeanBuffer getLoadContext() {
+  private LoadBeanBuffer getLoadContext() {
     return loadBuffer;
   }
 
-  /**
-   * Return the property that invoked the lazy loading.
-   */
-  public String getLazyLoadProperty() {
-    return lazyLoadProperty;
-  }
-
   public int getBatchSize() {
     return getLoadContext().getBatchSize();
   }
@@ -93,30 +82,14 @@ public class LoadBeanRequest extends LoadRequest {
   /**
    * Return the list of Id values for the beans in the lazy load buffer.
    */
-  public List<Object> getIdList(int batchSize) {
+  public List<Object> getIdList() {
 
-    List<Object> idList = new ArrayList<>(batchSize);
+    List<Object> idList = new ArrayList<>();
 
     BeanDescriptor<?> desc = loadBuffer.getBeanDescriptor();
     for (EntityBeanIntercept ebi : batch) {
-      EntityBean bean = ebi.getOwner();
-      idList.add(desc.getId(bean));
+      idList.add(desc.getId(ebi.getOwner()));
     }
-
-
-    if (!desc.isMultiValueIdSupported() && !idList.isEmpty()) {
-      int extraIds = batchSize - batch.size();
-      if (extraIds > 0) {
-        // for performance make up the Id's to the batch size
-        // so we get the same query (for Ebean and the db)
-        Object firstId = idList.get(0);
-        for (int i = 0; i < extraIds; i++) {
-          // just add the first Id again
-          idList.add(firstId);
-        }
-      }
-    }
-
     return idList;
   }
 

src/main/java/io/ebeaninternal/api/LoadManyRequest.java

@@ -3,6 +3,7 @@ package io.ebeaninternal.api;
 import io.ebean.bean.BeanCollection;
 import io.ebean.bean.EntityBean;
 import io.ebean.util.StringHelper;
+import io.ebeaninternal.server.core.BindPadding;
 import io.ebeaninternal.server.core.OrmQueryRequest;
 import io.ebeaninternal.server.deploy.BeanDescriptor;
 import io.ebeaninternal.server.deploy.BeanPropertyAssocMany;
@@ -65,13 +66,6 @@ public class LoadManyRequest extends LoadRequest {
     return batch;
   }
 
-  /**
-   * Return the load context.
-   */
-  public LoadManyBuffer getLoadContext() {
-    return loadContext;
-  }
-
   /**
    * Return true if lazy loading should only load the id values.
    * <p>
@@ -80,14 +74,14 @@ public class LoadManyRequest extends LoadRequest {
    * used.
    * </p>
    */
-  public boolean isOnlyIds() {
+  private boolean isOnlyIds() {
     return onlyIds;
   }
 
   /**
    * Return true if we should load the Collection ids into the cache.
    */
-  public boolean isLoadCache() {
+  private boolean isLoadCache() {
     return loadCache;
   }
 
@@ -98,22 +92,16 @@ public class LoadManyRequest extends LoadRequest {
     return loadContext.getBatchSize();
   }
 
-  private List<Object> getParentIdList(int batchSize) {
+  private List<Object> getParentIdList() {
 
-    ArrayList<Object> idList = new ArrayList<>(batchSize);
+    List<Object> idList = new ArrayList<>();
 
     BeanPropertyAssocMany<?> many = getMany();
     for (BeanCollection<?> bc : batch) {
       idList.add(many.getParentId(bc.getOwnerBean()));
     }
-    if (!many.getTargetDescriptor().isMultiValueIdSupported()) {
-      int extraIds = batchSize - batch.size();
-      if (extraIds > 0) {
-        Object firstId = idList.get(0);
-        for (int i = 0; i < extraIds; i++) {
-          idList.add(firstId);
-        }
-      }
+    if (many.getTargetDescriptor().isPadInExpression()) {
+      BindPadding.padIds(idList);
     }
 
     return idList;
@@ -123,7 +111,7 @@ public class LoadManyRequest extends LoadRequest {
     return loadContext.getBeanProperty();
   }
 
-  public SpiQuery<?> createQuery(SpiEbeanServer server, int batchSize) {
+  public SpiQuery<?> createQuery(SpiEbeanServer server) {
 
     BeanPropertyAssocMany<?> many = getMany();
 
@@ -142,10 +130,7 @@ public class LoadManyRequest extends LoadRequest {
     }
 
     query.setLazyLoadForParents(many);
-
-    List<Object> idList = getParentIdList(batchSize);
-    many.addWhereParentIdIn(query, idList, loadContext.isUseDocStore());
-
+    many.addWhereParentIdIn(query, getParentIdList(), loadContext.isUseDocStore());
     query.setPersistenceContext(loadContext.getPersistenceContext());
 
     String mode = isLazy() ? "+lazy" : "+query";

src/main/java/io/ebeaninternal/server/core/BindPadding.java

@@ -0,0 +1,57 @@
+package io.ebeaninternal.server.core;
+
+import java.util.List;
+
+/**
+ * Supports padding bind parameters for IN expressions.
+ * <p>
+ * We do this in order to get better hit ratio on DB query plans.
+ * </p>
+ */
+public final class BindPadding {
+
+  /**
+   * Pad out the Ids into common bucket sizes.
+   *
+   * @param idCollection The collection of Ids values being bound.
+   */
+  public static void padIds(List<Object> idCollection) {
+
+    int extraIds = padding(idCollection.size());
+    if (extraIds > 0) {
+      // for performance make up the Id's to the batch size
+      // so we get the same query (for Ebean and the db)
+      Object firstId = idCollection.get(0);
+      for (int i = 0; i < extraIds; i++) {
+        // just add the first Id again
+        idCollection.add(firstId);
+      }
+    }
+  }
+
+  /**
+   * Extra padding on binding id's in order to get better hit ratio on DB prepared statements / query plans.
+   */
+  static int padding(int size) {
+    if (size == 1) {
+      return 0;
+    }
+    if (size <= 5) {
+      return 5 - size;
+    }
+    if (size <= 10) {
+      return 10 - size;
+    }
+    if (size <= 20) {
+      return 20 - size;
+    }
+    if (size <= 40) {
+      return 40 - size;
+    }
+    if (size <= 50) {
+      return 50 - size;
+    }
+    return size <= 100 ? 100 - size : 0;
+  }
+
+}

src/main/java/io/ebeaninternal/server/core/DefaultBeanLoader.java

@@ -38,54 +38,14 @@ class DefaultBeanLoader {
     this.onIterateUseExtraTxn = server.getDatabasePlatform().useExtraTransactionOnIterateSecondaryQueries();
   }
 
-  /**
-   * Return a batch size that might be less than the requestedBatchSize.
-   * <p>
-   * This means we can have large and variable requestedBatchSizes.
-   * </p>
-   * <p>
-   * We want to restrict the number of different batch sizes as we want to
-   * re-use the query plan cache and get DB statement re-use.
-   * </p>
-   */
-  private int getBatchSize(int batchSize) {
-
-    if (batchSize == 1) {
-      // there is only one bean/collection to load
-      return 1;
-    }
-    if (batchSize <= 5) {
-      // anything less than 5 becomes 5
-      return 5;
-    }
-    if (batchSize <= 10) {
-      return 10;
-    }
-    if (batchSize <= 20) {
-      return 20;
-    }
-    if (batchSize <= 50) {
-      return 50;
-    }
-    if (batchSize <= 100) {
-      return 100;
-    }
-    return batchSize;
-  }
-
   void refreshMany(EntityBean parentBean, String propertyName) {
     refreshMany(parentBean, propertyName, null);
   }
 
   void loadMany(LoadManyRequest loadRequest) {
 
-    List<BeanCollection<?>> batch = loadRequest.getBatch();
-
-    int batchSize = getBatchSize(batch.size());
-
-    SpiQuery<?> query = loadRequest.createQuery(server, batchSize);
+    SpiQuery<?> query = loadRequest.createQuery(server);
     executeQuery(loadRequest, query);
-
     loadRequest.postLoad();
   }
 
@@ -97,7 +57,7 @@ class DefaultBeanLoader {
     loadManyInternal(parentBean, propertyName, null, false, onlyIds);
   }
 
-  void refreshMany(EntityBean parentBean, String propertyName, Transaction t) {
+  private void refreshMany(EntityBean parentBean, String propertyName, Transaction t) {
     loadManyInternal(parentBean, propertyName, t, true, false);
   }
 
@@ -147,8 +107,7 @@ class DefaultBeanLoader {
       query.setLoadDescription("+lazy", null);
     }
 
-    String idProperty = parentDesc.getIdBinder().getIdProperty();
-    query.select(idProperty);
+    query.select(parentDesc.getIdBinder().getIdProperty());
 
     if (onlyIds) {
       query.fetch(many.getName(), many.getTargetIdProperty());
@@ -192,9 +151,7 @@ class DefaultBeanLoader {
       throw new RuntimeException("Nothing in batch?");
     }
 
-    int batchSize = getBatchSize(batch.size());
-
-    List<Object> idList = loadRequest.getIdList(batchSize);
+    List<Object> idList = loadRequest.getIdList();
     if (idList.isEmpty()) {
       // everything was loaded from cache
       return;
@@ -315,6 +272,5 @@ class DefaultBeanLoader {
     }
 
     desc.resetManyProperties(dbBean);
-
   }
 }

src/main/java/io/ebeaninternal/server/core/OrmQueryRequest.java

@@ -115,6 +115,11 @@ public final class OrmQueryRequest<T> extends BeanRequest implements SpiOrmQuery
     }
   }
 
+  @Override
+  public boolean isPadInExpression() {
+    return beanDescriptor.isPadInExpression();
+  }
+
   @Override
   public boolean isMultiValueIdSupported() {
     return beanDescriptor.isMultiValueIdSupported();

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptor.java

@@ -1835,6 +1835,13 @@ public class BeanDescriptor<T> implements BeanType<T>, STreeType {
     return multiValueSupported && isSimpleId();
   }
 
+  /**
+   * Return true if Id IN expression should have bind parameters padded.
+   */
+  public boolean isPadInExpression() {
+    return !multiValueSupported && isSimpleId();
+  }
+
   /**
    * Return the sql for binding an id. This is the columns with table alias that
    * make up the id.

src/main/java/io/ebeaninternal/server/expression/IdInExpression.java

@@ -5,6 +5,7 @@ import io.ebeaninternal.api.ManyWhereJoins;
 import io.ebeaninternal.api.SpiExpression;
 import io.ebeaninternal.api.SpiExpressionRequest;
 import io.ebeaninternal.api.SpiExpressionValidation;
+import io.ebeaninternal.server.core.BindPadding;
 import io.ebeaninternal.server.deploy.BeanDescriptor;
 import io.ebeaninternal.server.deploy.id.IdBinder;
 
@@ -46,6 +47,10 @@ public class IdInExpression extends NonPrepareExpression {
   @Override
   public void prepareExpression(BeanQueryRequest<?> request) {
     multiValueIdSupported = request.isMultiValueIdSupported();
+    if (!multiValueIdSupported && !idCollection.isEmpty() && request.isPadInExpression()) {
+      // pad out the ids for better hit ratio on DB query plans
+      BindPadding.padIds(idCollection);
+    }
   }
 
   @Override

src/main/java/io/ebeaninternal/server/loadcontext/DLoadBeanContext.java

@@ -1,5 +1,6 @@
 package io.ebeaninternal.server.loadcontext;
 
+import io.ebean.CacheMode;
 import io.ebean.bean.BeanLoader;
 import io.ebean.bean.EntityBeanIntercept;
 import io.ebean.bean.PersistenceContext;
@@ -20,6 +21,8 @@ import java.util.Set;
  */
 class DLoadBeanContext extends DLoadBaseContext implements LoadBeanContext {
 
+  private final boolean cache;
+
   private List<LoadBuffer> bufferList;
 
   private LoadBuffer currentBuffer;
@@ -29,6 +32,7 @@ class DLoadBeanContext extends DLoadBaseContext implements LoadBeanContext {
     // bufferList only required when using query joins (queryFetch)
     this.bufferList = (!queryFetch) ? null : new ArrayList<>();
     this.currentBuffer = createBuffer(firstBatchSize);
+    this.cache = (queryProps == null) ? false : queryProps.isCache();
   }
 
   /**
@@ -43,6 +47,9 @@ class DLoadBeanContext extends DLoadBaseContext implements LoadBeanContext {
 
   private void configureQuery(SpiQuery<?> query, String lazyLoadProperty) {
 
+    if (cache) {
+      query.setBeanCacheMode(CacheMode.ON);
+    }
     setLabel(query);
     parent.propagateQueryState(query, desc.isDocStoreMapped());
     query.setParentNode(objectGraphNode);