Merge pull request #2792 from ebean-orm/feature/2782-fwdOnlyFetchSize

#2782 #2783 - Forward only fetchSize() for MySql and MariaDB is Integer.MIN_VALUE and 1 respectively

ebean-core/src/main/java/io/ebeaninternal/server/core/OrmQueryEngine.java

@@ -73,4 +73,6 @@ public interface OrmQueryEngine {
    * Return true if multi-value bind is supported for this type (and current platform).
    */
   boolean isMultiValueSupported(Class<?> valueType);
+
+  int forwardOnlyFetchSize();
 }

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

@@ -761,4 +761,8 @@ public final class OrmQueryRequest<T> extends BeanRequest implements SpiOrmQuery
   public boolean isInlineSqlUpdateLimit() {
     return query.getMaxRows() < 1 || server.databasePlatform().isInlineSqlUpdateLimit();
   }
+
+  public int forwardOnlyFetchSize() {
+    return queryEngine.forwardOnlyFetchSize();
+  }
 }

ebean-core/src/main/java/io/ebeaninternal/server/query/CQuery.java

@@ -314,7 +314,7 @@ public final class CQuery<T> implements DbReadContext, CancelableQuery, SpiProfi
       if (forwardOnlyHint) {
         // Use forward only hints for large resultSet processing (Issue 56, MySql specific)
         pstmt = conn.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
-        pstmt.setFetchSize(1);
+        pstmt.setFetchSize(request.forwardOnlyFetchSize());
       } else {
         pstmt = conn.prepareStatement(sql);
       }

ebean-core/src/main/java/io/ebeaninternal/server/query/CQueryEngine.java

@@ -3,6 +3,7 @@ package io.ebeaninternal.server.query;
 import io.ebean.QueryIterator;
 import io.ebean.ValuePair;
 import io.ebean.Version;
+import io.ebean.annotation.Platform;
 import io.ebean.bean.BeanCollection;
 import io.ebean.bean.EntityBean;
 import io.ebean.bean.ObjectGraphNode;
@@ -32,19 +33,13 @@ import java.util.*;
 public final class CQueryEngine {
 
   private static final Logger log = CoreLog.log;
-
   private static final String T0 = "t0";
 
   private final int defaultFetchSizeFindList;
-
   private final int defaultFetchSizeFindEach;
-
   private final boolean forwardOnlyHintOnFindIterate;
-
   private final CQueryBuilder queryBuilder;
-
   private final CQueryHistorySupport historySupport;
-
   private final DatabasePlatform dbPlatform;
 
   public CQueryEngine(DatabaseConfig config, DatabasePlatform dbPlatform, Binder binder, Map<String, String> asOfTableMapping, Map<String, String> draftTableMap) {
@@ -56,6 +51,11 @@ public final class CQueryEngine {
     this.queryBuilder = new CQueryBuilder(dbPlatform, binder, historySupport, new CQueryDraftSupport(draftTableMap));
   }
 
+  public int forwardOnlyFetchSize() {
+    Platform base = dbPlatform.getPlatform().base();
+    return Platform.MYSQL == base ? Integer.MIN_VALUE : 1;
+  }
+
   public <T> CQuery<T> buildQuery(OrmQueryRequest<T> request) {
     return queryBuilder.buildQuery(request);
   }

ebean-core/src/main/java/io/ebeaninternal/server/query/DefaultOrmQueryEngine.java

@@ -17,25 +17,19 @@ import javax.persistence.PersistenceException;
 import java.sql.SQLException;
 import java.util.Collection;
 import java.util.List;
-import java.util.Set;
 
-/**
- * Main Finder implementation.
- */
 public final class DefaultOrmQueryEngine implements OrmQueryEngine {
 
-  /**
-   * Find using predicates
-   */
   private final CQueryEngine queryEngine;
-
   private final Binder binder;
+  private final int forwardOnlyFetchSize;
 
   /**
    * Create the Finder.
    */
   public DefaultOrmQueryEngine(CQueryEngine queryEngine, Binder binder) {
     this.queryEngine = queryEngine;
+    this.forwardOnlyFetchSize = queryEngine.forwardOnlyFetchSize();
     this.binder = binder;
   }
 
@@ -44,6 +38,11 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
     return queryEngine.translate(request, bindLog, sql, e);
   }
 
+  @Override
+  public int forwardOnlyFetchSize() {
+    return forwardOnlyFetchSize;
+  }
+
   @Override
   public boolean isMultiValueSupported(Class<?> cls) {
     return binder.isMultiValueSupported(cls);
@@ -53,7 +52,6 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
    * Flushes the jdbc batch by default unless explicitly turned off on the transaction.
    */
   private <T> void flushJdbcBatchOnQuery(OrmQueryRequest<T> request) {
-
     SpiTransaction t = request.transaction();
     if (t.isFlushOnQuery()) {
       // before we perform a query, we need to flush any
@@ -65,14 +63,12 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
 
   @Override
   public <T> int delete(OrmQueryRequest<T> request) {
-
     flushJdbcBatchOnQuery(request);
     return queryEngine.delete(request);
   }
 
   @Override
   public <T> int update(OrmQueryRequest<T> request) {
-
     flushJdbcBatchOnQuery(request);
     return queryEngine.update(request);
   }
@@ -85,14 +81,12 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
 
   @Override
   public <T> int findCount(OrmQueryRequest<T> request) {
-
     flushJdbcBatchOnQuery(request);
     return queryEngine.findCount(request);
   }
 
   @Override
   public <A> List<A> findIds(OrmQueryRequest<?> request) {
-
     flushJdbcBatchOnQuery(request);
     return queryEngine.findIds(request);
   }
@@ -112,16 +106,13 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
 
   @Override
   public <T> List<Version<T>> findVersions(OrmQueryRequest<T> request) {
-
     flushJdbcBatchOnQuery(request);
     return queryEngine.findVersions(request);
   }
 
   @Override
   public <T> BeanCollection<T> findMany(OrmQueryRequest<T> request) {
-
     flushJdbcBatchOnQuery(request);
-
     BeanFindController finder = request.finder();
 
     BeanCollection<T> result;
@@ -131,13 +122,11 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
     } else {
       result = queryEngine.findMany(request);
     }
-
     if (finder != null) {
       result = finder.postProcessMany(request, result);
     }
 
     SpiQuery<T> query = request.query();
-
     if (result != null && request.isBeanCachePutMany()) {
       // load the individual beans into the bean cache
       BeanDescriptor<T> descriptor = request.descriptor();
@@ -146,7 +135,6 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
     }
 
     request.mergeCacheHits(result);
-
     if (request.isQueryCachePut()) {
       // load the query result into the query cache
       result.setReadOnly(true);
@@ -155,7 +143,6 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
         result = result.getShallowCopy();
       }
     }
-
     return result;
   }
 
@@ -164,9 +151,7 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
    */
   @Override
   public <T> T findId(OrmQueryRequest<T> request) {
-
     flushJdbcBatchOnQuery(request);
-
     BeanFindController finder = request.finder();
 
     T result;
@@ -175,15 +160,12 @@ public final class DefaultOrmQueryEngine implements OrmQueryEngine {
     } else {
       result = queryEngine.find(request);
     }
-
     if (finder != null) {
       result = finder.postProcess(request, result);
     }
-
     if (result != null && request.isBeanCachePut()) {
       request.descriptor().cacheBeanPut((EntityBean) result);
     }
-
     return result;
   }