Merge branch 'develop' into gburd/wip-facet-cache

bin/format.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+for f in $(find ./src -name \*.java); do
+  echo Formatting $f
+  java -jar ./lib/google-java-format-1.3-all-deps.jar --replace $f
+done
+

src/main/java/com/datastax/driver/core/querybuilder/IsNotNullClause.java

@@ -0,0 +1,48 @@
+/*
+ *      Copyright (C) 2015 The Helenus Authors
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ */
+package com.datastax.driver.core.querybuilder;
+
+import com.datastax.driver.core.CodecRegistry;
+import java.util.List;
+
+public class IsNotNullClause extends Clause {
+
+  final String name;
+
+  public IsNotNullClause(String name) {
+    this.name = name;
+  }
+
+  @Override
+  String name() {
+    return name;
+  }
+
+  @Override
+  Object firstValue() {
+    return null;
+  }
+
+  @Override
+  void appendTo(StringBuilder sb, List<Object> variables, CodecRegistry codecRegistry) {
+    Utils.appendName(name, sb).append(" IS NOT NULL");
+  }
+
+  @Override
+  boolean containsBindMarker() {
+    return false;
+  }
+}

src/main/java/com/datastax/driver/core/schemabuilder/CreateMaterializedView.java

@@ -0,0 +1,53 @@
+package com.datastax.driver.core.schemabuilder;
+
+import com.datastax.driver.core.CodecRegistry;
+import com.datastax.driver.core.querybuilder.Select;
+
+public class CreateMaterializedView extends Create {
+
+  private String viewName;
+  private Select.Where selection;
+  private String primaryKey;
+  private String clustering;
+
+  public CreateMaterializedView(
+      String keyspaceName, String viewName, Select.Where selection, String primaryKey, String clustering) {
+    super(keyspaceName, viewName);
+    this.viewName = viewName;
+    this.selection = selection;
+    this.primaryKey = primaryKey;
+    this.clustering = clustering;
+  }
+
+  public String getQueryString(CodecRegistry codecRegistry) {
+    return buildInternal();
+  }
+
+  public String buildInternal() {
+    StringBuilder createStatement =
+        new StringBuilder(STATEMENT_START).append("CREATE MATERIALIZED VIEW");
+    if (ifNotExists) {
+      createStatement.append(" IF NOT EXISTS");
+    }
+    createStatement.append(" ");
+    if (keyspaceName.isPresent()) {
+      createStatement.append(keyspaceName.get()).append(".");
+    }
+    createStatement.append(viewName);
+    createStatement.append(" AS ");
+    createStatement.append(selection.getQueryString());
+    createStatement.setLength(createStatement.length() - 1);
+    createStatement.append(" ");
+    createStatement.append(primaryKey);
+    if (clustering != null) {
+        createStatement.append(" ").append(clustering);
+    }
+    createStatement.append(";");
+
+    return createStatement.toString();
+  }
+
+  public String toString() {
+    return buildInternal();
+  }
+}

src/main/java/com/datastax/driver/core/schemabuilder/DropMaterializedView.java

@@ -0,0 +1,53 @@
+package com.datastax.driver.core.schemabuilder;
+
+import com.google.common.base.Optional;
+
+public class DropMaterializedView extends Drop {
+
+  enum DroppedItem {
+    TABLE,
+    TYPE,
+    INDEX,
+    MATERIALIZED_VIEW
+  }
+
+  private Optional<String> keyspaceName = Optional.absent();
+  private String itemName;
+  private boolean ifExists = true;
+  private final String itemType = "MATERIALIZED VIEW";
+
+  public DropMaterializedView(String keyspaceName, String viewName) {
+    this(keyspaceName, viewName, DroppedItem.MATERIALIZED_VIEW);
+  }
+
+  private DropMaterializedView(String keyspaceName, String viewName, DroppedItem itemType) {
+    super(keyspaceName, viewName, Drop.DroppedItem.TABLE);
+    validateNotEmpty(keyspaceName, "Keyspace name");
+    this.keyspaceName = Optional.fromNullable(keyspaceName);
+    this.itemName = viewName;
+  }
+
+  /**
+   * Add the 'IF EXISTS' condition to this DROP statement.
+   *
+   * @return this statement.
+   */
+  public Drop ifExists() {
+    this.ifExists = true;
+    return this;
+  }
+
+  @Override
+  public String buildInternal() {
+    StringBuilder dropStatement = new StringBuilder("DROP " + itemType + " ");
+    if (ifExists) {
+      dropStatement.append("IF EXISTS ");
+    }
+    if (keyspaceName.isPresent()) {
+      dropStatement.append(keyspaceName.get()).append(".");
+    }
+
+    dropStatement.append(itemName);
+    return dropStatement.toString();
+  }
+}

src/main/java/net/helenus/core/HelenusSession.java

@@ -182,11 +182,11 @@ public final class HelenusSession extends AbstractSessionOperations implements C
     return metadata;
   }
 
-  public synchronized <T extends UnitOfWork> T begin() {
+  public synchronized UnitOfWork begin() {
     return begin(null);
   }
 
-  public synchronized <T extends UnitOfWork> T begin(T parent) {
+  public synchronized UnitOfWork begin(UnitOfWork parent) {
     try {
       Class<? extends UnitOfWork> clazz = unitOfWorkClass;
       Constructor<? extends UnitOfWork> ctor =
@@ -195,7 +195,7 @@ public final class HelenusSession extends AbstractSessionOperations implements C
       if (parent != null) {
         parent.addNestedUnitOfWork(uow);
       }
-      return (T) uow.begin();
+      return uow.begin();
     } catch (NoSuchMethodException
         | InvocationTargetException
         | InstantiationException

src/main/java/net/helenus/core/SchemaUtil.java

@@ -17,16 +17,22 @@ package net.helenus.core;
 
 import com.datastax.driver.core.*;
 import com.datastax.driver.core.IndexMetadata;
+import com.datastax.driver.core.querybuilder.IsNotNullClause;
+import com.datastax.driver.core.querybuilder.QueryBuilder;
+import com.datastax.driver.core.querybuilder.Select;
 import com.datastax.driver.core.schemabuilder.*;
 import com.datastax.driver.core.schemabuilder.Create.Options;
 import java.util.*;
 import java.util.stream.Collectors;
+import net.helenus.core.reflect.HelenusPropertyNode;
 import net.helenus.mapping.*;
 import net.helenus.mapping.ColumnType;
+import net.helenus.mapping.annotation.ClusteringColumn;
 import net.helenus.mapping.type.OptionalColumnMetadata;
 import net.helenus.support.CqlUtil;
 import net.helenus.support.HelenusMappingException;
 
+
 public final class SchemaUtil {
 
   private SchemaUtil() {}
@@ -143,6 +149,79 @@ public final class SchemaUtil {
     return SchemaBuilder.dropType(type.getTypeName()).ifExists();
   }
 
+  public static SchemaStatement createMaterializedView(
+      String keyspace, String viewName, HelenusEntity entity) {
+    if (entity.getType() != HelenusEntityType.VIEW) {
+      throw new HelenusMappingException("expected view entity " + entity);
+    }
+
+    if (entity == null) {
+      throw new HelenusMappingException("no entity or table to select data");
+    }
+
+    List<HelenusPropertyNode> props = new ArrayList<HelenusPropertyNode>();
+    entity
+        .getOrderedProperties()
+        .stream()
+        .map(p -> new HelenusPropertyNode(p, Optional.empty()))
+        .forEach(p -> props.add(p));
+
+    Select.Selection selection = QueryBuilder.select();
+
+    for (HelenusPropertyNode prop : props) {
+      String columnName = prop.getColumnName();
+      selection = selection.column(columnName);
+    }
+    Class<?> iface = entity.getMappingInterface();
+    String tableName = Helenus.entity(iface.getInterfaces()[0]).getName().toCql();
+    Select.Where where = selection.from(tableName).where();
+    List<String> p = new ArrayList<String>(props.size());
+    List<String> c = new ArrayList<String>(props.size());
+    List<String> o = new ArrayList<String>(props.size());
+
+    for (HelenusPropertyNode prop : props) {
+      String columnName = prop.getColumnName();
+      switch (prop.getProperty().getColumnType()) {
+        case PARTITION_KEY:
+          p.add(columnName);
+          where = where.and(new IsNotNullClause(columnName));
+          break;
+
+        case CLUSTERING_COLUMN:
+          c.add(columnName);
+          where = where.and(new IsNotNullClause(columnName));
+
+          ClusteringColumn clusteringColumn = prop.getProperty().getGetterMethod().getAnnotation(ClusteringColumn.class);
+          if (clusteringColumn != null && clusteringColumn.ordering() != null) {
+            o.add(columnName + " " + clusteringColumn.ordering().cql());
+          }
+          break;
+        default:
+          break;
+      }
+    }
+
+    String primaryKey =
+        "PRIMARY KEY ("
+            + ((p.size() > 1) ? "(" + String.join(", ", p) + ")" : p.get(0))
+            + ((c.size() > 0)
+                ? ", " + ((c.size() > 1) ? "(" + String.join(", ", c) + ")" : c.get(0))
+                : "")
+            + ")";
+
+    String clustering = "";
+    if (o.size() > 0) {
+        clustering = "WITH CLUSTERING ORDER BY (" + String.join(", ", o) + ")";
+    }
+    return new CreateMaterializedView(keyspace, viewName, where, primaryKey, clustering)
+            .ifNotExists();
+  }
+
+  public static SchemaStatement dropMaterializedView(
+      String keyspace, String viewName, HelenusEntity entity) {
+    return new DropMaterializedView(keyspace, viewName);
+  }
+
   public static SchemaStatement createTable(HelenusEntity entity) {
 
     if (entity.getType() != HelenusEntityType.TABLE) {

src/main/java/net/helenus/core/SessionInitializer.java

@@ -277,7 +277,7 @@ public final class SessionInitializer extends AbstractSessionOperations {
           }
 
           DslExportable dsl = (DslExportable) Helenus.dsl(iface);
-          dsl.setMetadata(session.getCluster().getMetadata());
+          dsl.setCassandraMetadataForHelenusSesion(session.getCluster().getMetadata());
           sessionRepository.add(dsl);
         });
 
@@ -287,8 +287,16 @@ public final class SessionInitializer extends AbstractSessionOperations {
     switch (autoDdl) {
       case CREATE_DROP:
 
-        // Drop tables first, otherwise a `DROP TYPE ...` will fail as the type is still referenced
-        // by a table.
+        // Drop view first, otherwise a `DROP TABLE ...` will fail as the type is still referenced
+        // by a view.
+        sessionRepository
+            .entities()
+            .stream()
+            .filter(e -> e.getType() == HelenusEntityType.VIEW)
+            .forEach(e -> tableOps.dropView(e));
+
+        // Drop tables second, before DROP TYPE otherwise a `DROP TYPE ...` will fail as the type is
+        // still referenced by a table.
         sessionRepository
             .entities()
             .stream()
@@ -307,6 +315,12 @@ public final class SessionInitializer extends AbstractSessionOperations {
             .filter(e -> e.getType() == HelenusEntityType.TABLE)
             .forEach(e -> tableOps.createTable(e));
 
+        sessionRepository
+            .entities()
+            .stream()
+            .filter(e -> e.getType() == HelenusEntityType.VIEW)
+            .forEach(e -> tableOps.createView(e));
+
         break;
 
       case VALIDATE:
@@ -317,16 +331,29 @@ public final class SessionInitializer extends AbstractSessionOperations {
             .stream()
             .filter(e -> e.getType() == HelenusEntityType.TABLE)
             .forEach(e -> tableOps.validateTable(getTableMetadata(e), e));
+
         break;
 
       case UPDATE:
         eachUserTypeInOrder(userTypeOps, e -> userTypeOps.updateUserType(getUserType(e), e));
 
+        sessionRepository
+            .entities()
+            .stream()
+            .filter(e -> e.getType() == HelenusEntityType.VIEW)
+            .forEach(e -> tableOps.dropView(e));
+
         sessionRepository
             .entities()
             .stream()
             .filter(e -> e.getType() == HelenusEntityType.TABLE)
             .forEach(e -> tableOps.updateTable(getTableMetadata(e), e));
+
+        sessionRepository
+            .entities()
+            .stream()
+            .filter(e -> e.getType() == HelenusEntityType.VIEW)
+            .forEach(e -> tableOps.createView(e));
         break;
     }
 

src/main/java/net/helenus/core/TableOperations.java

@@ -35,14 +35,11 @@ public final class TableOperations {
   }
 
   public void createTable(HelenusEntity entity) {
-
     sessionOps.execute(SchemaUtil.createTable(entity), true);
-
     executeBatch(SchemaUtil.createIndexes(entity));
   }
 
   public void dropTable(HelenusEntity entity) {
-
     sessionOps.execute(SchemaUtil.dropTable(entity), true);
   }
 
@@ -50,7 +47,10 @@ public final class TableOperations {
 
     if (tmd == null) {
       throw new HelenusException(
-          "table not exists " + entity.getName() + "for entity " + entity.getMappingInterface());
+          "table does not exists "
+              + entity.getName()
+              + "for entity "
+              + entity.getMappingInterface());
     }
 
     List<SchemaStatement> list = SchemaUtil.alterTable(tmd, entity, dropUnusedColumns);
@@ -67,7 +67,31 @@ public final class TableOperations {
   }
 
   public void updateTable(TableMetadata tmd, HelenusEntity entity) {
+    if (tmd == null) {
+      createTable(entity);
+      return;
+    }
 
+    executeBatch(SchemaUtil.alterTable(tmd, entity, dropUnusedColumns));
+    executeBatch(SchemaUtil.alterIndexes(tmd, entity, dropUnusedIndexes));
+  }
+
+  public void createView(HelenusEntity entity) {
+    sessionOps.execute(
+        SchemaUtil.createMaterializedView(
+            sessionOps.usingKeyspace(), entity.getName().toCql(), entity),
+        true);
+    //    executeBatch(SchemaUtil.createIndexes(entity)); NOTE: Unfortunately C* 3.10 does not yet support 2i on materialized views.
+  }
+
+  public void dropView(HelenusEntity entity) {
+    sessionOps.execute(
+        SchemaUtil.dropMaterializedView(
+            sessionOps.usingKeyspace(), entity.getName().toCql(), entity),
+        true);
+  }
+
+  public void updateView(TableMetadata tmd, HelenusEntity entity) {
     if (tmd == null) {
       createTable(entity);
       return;

src/main/java/net/helenus/core/operation/AbstractOptionalOperation.java

@@ -21,13 +21,11 @@ import com.datastax.driver.core.ResultSet;
 import com.google.common.base.Function;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
-
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
-
 import net.helenus.core.AbstractSessionOperations;
 import net.helenus.core.Filter;
 import net.helenus.core.Helenus;
@@ -173,5 +171,4 @@ public abstract class AbstractOptionalOperation<E, O extends AbstractOptionalOpe
     if (uow == null) return async();
     return CompletableFuture.<Optional<E>>supplyAsync(() -> sync(uow));
   }
-
 }

src/main/java/net/helenus/core/operation/InsertOperation.java

@@ -83,9 +83,18 @@ public final class InsertOperation<T> extends AbstractOperation<T, InsertOperati
     Set<String> keys = (mutations == null) ? null : mutations;
 
     for (HelenusProperty prop : properties) {
+      boolean addProp = false;
 
-      if (keys == null || keys.contains(prop.getPropertyName())) {
+      switch (prop.getColumnType()) {
+        case PARTITION_KEY:
+        case CLUSTERING_COLUMN:
+          addProp = true;
+          break;
+        default:
+          addProp = (keys == null || keys.contains(prop.getPropertyName()));
+      }
 
+      if (addProp) {
         Object value = BeanColumnValueProvider.INSTANCE.getColumnValue(pojo, -1, prop);
         value = sessionOps.getValuePreparer().prepareColumnValue(value, prop);
 

src/main/java/net/helenus/core/operation/SelectOperation.java

@@ -22,6 +22,7 @@ import com.datastax.driver.core.querybuilder.QueryBuilder;
 import com.datastax.driver.core.querybuilder.Select;
 import com.datastax.driver.core.querybuilder.Select.Selection;
 import com.datastax.driver.core.querybuilder.Select.Where;
+import com.google.common.base.Joiner;
 import com.google.common.collect.Iterables;
 import java.util.*;
 import java.util.function.Function;
@@ -47,6 +48,7 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
   protected List<Ordering> ordering = null;
   protected Integer limit = null;
   protected boolean allowFiltering = false;
+  protected String alternateTableName = null;
 
   @SuppressWarnings("unchecked")
   public SelectOperation(AbstractSessionOperations sessionOperations) {
@@ -128,6 +130,19 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
     return new CountOperation(sessionOps, entity);
   }
 
+  public <V extends E> SelectOperation<E> from(Class<V> materializedViewClass) {
+    Objects.requireNonNull(materializedViewClass);
+    HelenusEntity entity = Helenus.entity(materializedViewClass);
+    this.alternateTableName = entity.getName().toCql();
+    this.props.clear();
+    entity
+        .getOrderedProperties()
+        .stream()
+        .map(p -> new HelenusPropertyNode(p, Optional.empty()))
+        .forEach(p -> this.props.add(p));
+    return this;
+  }
+
   public SelectFirstOperation<E> single() {
     limit(1);
     return new SelectFirstOperation<E>(this);
@@ -231,6 +246,7 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
                 + prop.getEntity().getMappingInterface());
       }
 
+      /* TODO: is this useful information to gather when caching?
       if (cached) {
         switch (prop.getProperty().getColumnType()) {
           case PARTITION_KEY:
@@ -249,13 +265,15 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
             break;
         }
       }
+      */
     }
 
     if (entity == null) {
       throw new HelenusMappingException("no entity or table to select data");
     }
 
-    Select select = selection.from(entity.getName().toCql());
+    String tableName = alternateTableName == null ? entity.getName().toCql() : alternateTableName;
+    Select select = selection.from(tableName);
 
     if (ordering != null && !ordering.isEmpty()) {
       select.orderBy(ordering.toArray(new Ordering[ordering.size()]));

src/main/java/net/helenus/core/reflect/DslExportable.java

@@ -22,11 +22,11 @@ public interface DslExportable {
 
   public static final String GET_ENTITY_METHOD = "getHelenusMappingEntity";
   public static final String GET_PARENT_METHOD = "getParentDslHelenusPropertyNode";
-  public static final String SET_METADATA_METHOD = "setMetadata";
+  public static final String SET_METADATA_METHOD = "setCassandraMetadataForHelenusSesion";
 
   HelenusEntity getHelenusMappingEntity();
 
   HelenusPropertyNode getParentDslHelenusPropertyNode();
 
-  void setMetadata(Metadata metadata);
+  void setCassandraMetadataForHelenusSesion(Metadata metadata);
 }

src/main/java/net/helenus/core/reflect/DslInvocationHandler.java

@@ -59,7 +59,7 @@ public class DslInvocationHandler<E> implements InvocationHandler {
     this.classLoader = classLoader;
   }
 
-  public void setMetadata(Metadata metadata) {
+  public void setCassandraMetadataForHelenusSesion(Metadata metadata) {
     if (metadata != null) {
       this.metadata = metadata;
       entity = init(metadata);
@@ -130,7 +130,7 @@ public class DslInvocationHandler<E> implements InvocationHandler {
         && args.length == 1
         && args[0] instanceof Metadata) {
       if (metadata == null) {
-        this.setMetadata((Metadata) args[0]);
+        this.setCassandraMetadataForHelenusSesion((Metadata) args[0]);
       }
       return null;
     }

src/main/java/net/helenus/mapping/HelenusEntityType.java

@@ -17,6 +17,7 @@ package net.helenus.mapping;
 
 public enum HelenusEntityType {
   TABLE,
+  VIEW,
   TUPLE,
   UDT;
 }

src/main/java/net/helenus/mapping/HelenusMappingEntity.java

@@ -185,6 +185,9 @@ public final class HelenusMappingEntity implements HelenusEntity {
       case TABLE:
         return MappingUtil.getTableName(iface, true);
 
+      case VIEW:
+        return MappingUtil.getViewName(iface, true);
+
       case TUPLE:
         return IdentityName.of(MappingUtil.getDefaultEntityName(iface), false);
 
@@ -201,6 +204,8 @@ public final class HelenusMappingEntity implements HelenusEntity {
 
     if (null != iface.getDeclaredAnnotation(Table.class)) {
       return HelenusEntityType.TABLE;
+    } else if (null != iface.getDeclaredAnnotation(MaterializedView.class)) {
+      return HelenusEntityType.VIEW;
     } else if (null != iface.getDeclaredAnnotation(Tuple.class)) {
       return HelenusEntityType.TUPLE;
     } else if (null != iface.getDeclaredAnnotation(UDT.class)) {

src/main/java/net/helenus/mapping/MappingUtil.java

@@ -25,10 +25,7 @@ import javax.validation.ConstraintValidator;
 import net.helenus.core.Getter;
 import net.helenus.core.Helenus;
 import net.helenus.core.reflect.*;
-import net.helenus.mapping.annotation.Index;
-import net.helenus.mapping.annotation.Table;
-import net.helenus.mapping.annotation.Tuple;
-import net.helenus.mapping.annotation.UDT;
+import net.helenus.mapping.annotation.*;
 import net.helenus.support.DslPropertyException;
 import net.helenus.support.HelenusMappingException;
 
@@ -172,6 +169,28 @@ public final class MappingUtil {
     return udt != null;
   }
 
+  public static IdentityName getViewName(Class<?> iface, boolean required) {
+
+    String viewName = null;
+    boolean forceQuote = false;
+
+    MaterializedView view = iface.getDeclaredAnnotation(MaterializedView.class);
+
+    if (view != null) {
+      viewName = view.value();
+      forceQuote = view.forceQuote();
+
+    } else if (required) {
+      throw new HelenusMappingException("entity must have annotation @Table " + iface);
+    }
+
+    if (viewName == null || viewName.isEmpty()) {
+      viewName = getDefaultEntityName(iface);
+    }
+
+    return new IdentityName(viewName, forceQuote);
+  }
+
   public static IdentityName getTableName(Class<?> iface, boolean required) {
 
     String tableName = null;
@@ -222,6 +241,7 @@ public final class MappingUtil {
         }
 
         if (iface.getDeclaredAnnotation(Table.class) != null
+            || iface.getDeclaredAnnotation(MaterializedView.class) != null
             || iface.getDeclaredAnnotation(UDT.class) != null
             || iface.getDeclaredAnnotation(Tuple.class) != null) {
 

src/main/java/net/helenus/mapping/annotation/CoveringIndex.java

@@ -0,0 +1,50 @@
+package net.helenus.mapping.annotation;
+
+import java.lang.annotation.*;
+
+/**
+ * CoveringIndex annotation is using under the specific column or method in entity interface
+ * with @Table annotation.
+ *
+ * <p>A corresponding materialized view will be created based on the underline @Table for the
+ * specific column.
+ *
+ * <p>This is useful when you need to perform IN or SORT/ORDER-BY queries and to do so you'll need
+ * different materialized table on disk in Cassandra.
+ *
+ * <p>For each @Table annotated interface Helenus will create/update/verify Cassandra Materialized
+ * Views and some indexes if needed on startup.
+ */
+@Inherited
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE})
+public @interface CoveringIndex {
+
+  /**
+   * Defined the name of the index. By default the entity name with column name as suffix.
+   *
+   * @return name of the covering index
+   */
+  String name() default "";
+
+  /**
+   * Set of fields in this entity to replicate in the index.
+   *
+   * @return array of the string names of the fields.
+   */
+  String[] covering() default "";
+
+  /**
+   * Set of fields to use as the partition keys for this projection.
+   *
+   * @return array of the string names of the fields.
+   */
+  String[] partitionKeys() default "";
+
+  /**
+   * Set of fields to use as the clustering columns for this projection.
+   *
+   * @return array of the string names of the fields.
+   */
+  String[] clusteringColumns() default "";
+}

src/main/java/net/helenus/mapping/annotation/MaterializedView.java

@@ -0,0 +1,52 @@
+/*
+ *      Copyright (C) 2015 The Helenus Authors
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ */
+package net.helenus.mapping.annotation;
+
+import java.lang.annotation.*;
+
+/**
+ * Materialized alternate view of another Entity annotation
+ *
+ * <p>MaterializedView annotation is used to define different mapping to some other Table interface
+ *
+ * <p>This is useful when you need to perform IN or SORT/ORDER-BY queries and to do so you'll need
+ * different materialized table on disk in Cassandra.
+ *
+ * <p>For each @Table annotated interface Helenus will create/update/verify Cassandra Materialized
+ * Views and some indexes if needed on startup.
+ */
+@Inherited
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE})
+public @interface MaterializedView {
+
+  /**
+   * Default value is the SimpleName of the interface normalized to underscore
+   *
+   * @return name of the type
+   */
+  String value() default "";
+
+  /**
+   * For reserved words in Cassandra we need quotation in CQL queries. This property marks that the
+   * name of the type needs to be quoted.
+   *
+   * <p>Default value is false, we are quoting only selected names.
+   *
+   * @return true if name have to be quoted
+   */
+  boolean forceQuote() default false;
+}

src/test/java/net/helenus/test/integration/core/views/Cyclist.java

@@ -0,0 +1,29 @@
+package net.helenus.test.integration.core.views;
+
+import java.util.Date;
+import java.util.UUID;
+import net.helenus.mapping.annotation.ClusteringColumn;
+import net.helenus.mapping.annotation.CoveringIndex;
+import net.helenus.mapping.annotation.PartitionKey;
+import net.helenus.mapping.annotation.Table;
+
+@Table
+@CoveringIndex(
+  name = "cyclist_mv",
+  covering = {"age", "birthday", "country"},
+  partitionKeys = {"age", "cid"},
+  clusteringColumns = {}
+)
+public interface Cyclist {
+  @ClusteringColumn
+  UUID cid();
+
+  String name();
+
+  @PartitionKey
+  int age();
+
+  Date birthday();
+
+  String country();
+}

src/test/java/net/helenus/test/integration/core/views/CyclistsByAge.java

@@ -0,0 +1,21 @@
+package net.helenus.test.integration.core.views;
+
+import java.util.Date;
+import java.util.UUID;
+
+import net.helenus.mapping.OrderingDirection;
+import net.helenus.mapping.annotation.*;
+
+@MaterializedView
+public interface CyclistsByAge extends Cyclist {
+  @PartitionKey
+  UUID cid();
+
+  @ClusteringColumn(ordering = OrderingDirection.ASC)
+  int age();
+
+  Date birthday();
+
+  @Index
+  String country();
+}

src/test/java/net/helenus/test/integration/core/views/MaterializedViewTest.java

@@ -0,0 +1,77 @@
+/*
+ *      Copyright (C) 2015 The Helenus Authors
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ */
+package net.helenus.test.integration.core.views;
+
+import static net.helenus.core.Query.eq;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.*;
+import net.helenus.core.Helenus;
+import net.helenus.core.HelenusSession;
+import net.helenus.test.integration.build.AbstractEmbeddedCassandraTest;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+// See: https://docs.datastax.com/en/cql/3.3/cql/cql_using/useCreateMV.html
+//      https://docs.datastax.com/en/cql/3.3/cql/cql_reference/cqlCreateMaterializedView.html
+//      https://www.datastax.com/dev/blog/materialized-view-performance-in-cassandra-3-x
+//      https://cassandra-zone.com/materialized-views/
+public class MaterializedViewTest extends AbstractEmbeddedCassandraTest {
+
+  static Cyclist cyclist;
+  static HelenusSession session;
+
+  static Date dateFromString(String dateInString) {
+    SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yyyy");
+    try {
+      return formatter.parse(dateInString);
+    } catch (ParseException e) {
+      e.printStackTrace();
+    }
+    return null;
+  }
+
+  @BeforeClass
+  public static void beforeTest() {
+    session =
+        Helenus.init(getSession())
+            .showCql()
+            .add(Cyclist.class)
+            .add(CyclistsByAge.class)
+            .autoCreateDrop()
+            .get();
+    cyclist = session.dsl(Cyclist.class);
+
+    session
+        .insert(cyclist)
+        .value(cyclist::cid, UUID.randomUUID())
+        .value(cyclist::age, 18)
+        .value(cyclist::birthday, dateFromString("1997-02-08"))
+        .value(cyclist::country, "Netherlands")
+        .value(cyclist::name, "Pascal EENKHOORN")
+        .sync();
+  }
+
+  @Test
+  public void testMv() throws Exception {
+    session
+        .select(Cyclist.class)
+        .from(CyclistsByAge.class)
+        .where(cyclist::age, eq(18))
+        .sync();
+  }
+}