diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java
index d350789..4596393 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java
@@ -43,41 +43,42 @@
 import org.apache.hyracks.storage.am.common.api.ITupleFilterFactory;
 
 public interface IMetadataProvider<S, I> {
-    public IDataSource<S> findDataSource(S id) throws AlgebricksException;
+    IDataSource<S> findDataSource(S id) throws AlgebricksException;
 
     /**
      * Obs: A scanner may choose to contribute a null
      * AlgebricksPartitionConstraint and implement
      * contributeSchedulingConstraints instead.
      */
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getScannerRuntime(IDataSource<S> dataSource,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getScannerRuntime(IDataSource<S> dataSource,
             List<LogicalVariable> scanVariables, List<LogicalVariable> projectVariables, boolean projectPushed,
             List<LogicalVariable> minFilterVars, List<LogicalVariable> maxFilterVars,
             ITupleFilterFactory tupleFilterFactory, long outputLimit, IOperatorSchema opSchema,
             IVariableTypeEnvironment typeEnv, JobGenContext context, JobSpecification jobSpec, Object implConfig,
-            IProjectionInfo<?> projectionInfo) throws AlgebricksException;
+            IProjectionFiltrationInfo<?> projectionInfo, IProjectionFiltrationInfo<?> metaProjectionInfo)
+            throws AlgebricksException;
 
-    public Pair<IPushRuntimeFactory, AlgebricksPartitionConstraint> getWriteFileRuntime(IDataSink sink,
-            int[] printColumns, IPrinterFactory[] printerFactories, IAWriterFactory writerFactory,
-            RecordDescriptor inputDesc) throws AlgebricksException;
+    Pair<IPushRuntimeFactory, AlgebricksPartitionConstraint> getWriteFileRuntime(IDataSink sink, int[] printColumns,
+            IPrinterFactory[] printerFactories, IAWriterFactory writerFactory, RecordDescriptor inputDesc)
+            throws AlgebricksException;
 
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getResultHandleRuntime(IDataSink sink,
-            int[] printColumns, IPrinterFactory[] printerFactories, IAWriterFactory writerFactory,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getResultHandleRuntime(IDataSink sink, int[] printColumns,
+            IPrinterFactory[] printerFactories, IAWriterFactory writerFactory,
             IResultSerializerFactoryProvider resultSerializerFactoryProvider, RecordDescriptor inputDesc,
             IResultMetadata metadata, JobSpecification spec) throws AlgebricksException;
 
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getWriteResultRuntime(IDataSource<S> dataSource,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getWriteResultRuntime(IDataSource<S> dataSource,
             IOperatorSchema propagatedSchema, List<LogicalVariable> keys, LogicalVariable payLoadVar,
             List<LogicalVariable> additionalNonKeyFields, JobGenContext context, JobSpecification jobSpec)
             throws AlgebricksException;
 
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getInsertRuntime(IDataSource<S> dataSource,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getInsertRuntime(IDataSource<S> dataSource,
             IOperatorSchema propagatedSchema, IVariableTypeEnvironment typeEnv, List<LogicalVariable> keys,
             LogicalVariable payLoadVar, List<LogicalVariable> additionalFilterKeyFields,
             List<LogicalVariable> additionalNonFilteringFields, RecordDescriptor inputRecordDesc, JobGenContext context,
             JobSpecification jobSpec, boolean bulkload) throws AlgebricksException;
 
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getDeleteRuntime(IDataSource<S> dataSource,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getDeleteRuntime(IDataSource<S> dataSource,
             IOperatorSchema propagatedSchema, IVariableTypeEnvironment typeEnv, List<LogicalVariable> keys,
             LogicalVariable payLoadVar, List<LogicalVariable> additionalNonKeyFields,
             List<LogicalVariable> additionalNonFilteringFields, RecordDescriptor inputRecordDesc, JobGenContext context,
@@ -87,42 +88,28 @@
      * Creates the insert runtime of IndexInsertDeletePOperator, which models
      * insert/delete operations into a secondary index.
      *
-     * @param dataSource
-     *            Target secondary index.
-     * @param propagatedSchema
-     *            Output schema of the insert/delete operator to be created.
-     * @param inputSchemas
-     *            Output schemas of the insert/delete operator to be created.
-     * @param typeEnv
-     *            Type environment of the original IndexInsertDeleteOperator operator.
-     * @param primaryKeys
-     *            Variables for the dataset's primary keys that the dataSource secondary index belongs to.
-     * @param secondaryKeys
-     *            Variables for the secondary-index keys.
-     * @param additionalNonKeyFields
-     *            Additional variables that can be passed to the secondary index as payload.
-     *            This can be useful when creating a second filter on a non-primary and non-secondary
-     *            fields for additional pruning power.
-     * @param filterExpr
-     *            Filtering expression to be pushed inside the runtime op.
-     *            Such a filter may, e.g., exclude NULLs from being inserted/deleted.
-     * @param recordDesc
-     *            Output record descriptor of the runtime op to be created.
-     * @param context
-     *            Job generation context.
-     * @param spec
-     *            Target job specification.
-     * @param secondaryKeysPipelines
-     *            Nested plans to extract secondary keys.
-     * @param pipelineTopSchema
-     *            Schema of the primary pipeline for secondary keys.
-     * @return
-     *         A Hyracks IOperatorDescriptor and its partition constraint.
+     * @param dataSource             Target secondary index.
+     * @param propagatedSchema       Output schema of the insert/delete operator to be created.
+     * @param inputSchemas           Output schemas of the insert/delete operator to be created.
+     * @param typeEnv                Type environment of the original IndexInsertDeleteOperator operator.
+     * @param primaryKeys            Variables for the dataset's primary keys that the dataSource secondary index belongs to.
+     * @param secondaryKeys          Variables for the secondary-index keys.
+     * @param additionalNonKeyFields Additional variables that can be passed to the secondary index as payload.
+     *                               This can be useful when creating a second filter on a non-primary and non-secondary
+     *                               fields for additional pruning power.
+     * @param filterExpr             Filtering expression to be pushed inside the runtime op.
+     *                               Such a filter may, e.g., exclude NULLs from being inserted/deleted.
+     * @param recordDesc             Output record descriptor of the runtime op to be created.
+     * @param context                Job generation context.
+     * @param spec                   Target job specification.
+     * @param secondaryKeysPipelines Nested plans to extract secondary keys.
+     * @param pipelineTopSchema      Schema of the primary pipeline for secondary keys.
+     * @return A Hyracks IOperatorDescriptor and its partition constraint.
      * @throws AlgebricksException
      */
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getIndexInsertRuntime(
-            IDataSourceIndex<I, S> dataSource, IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas,
-            IVariableTypeEnvironment typeEnv, List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getIndexInsertRuntime(IDataSourceIndex<I, S> dataSource,
+            IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas, IVariableTypeEnvironment typeEnv,
+            List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys,
             List<LogicalVariable> additionalNonKeyFields, ILogicalExpression filterExpr, RecordDescriptor recordDesc,
             JobGenContext context, JobSpecification spec, boolean bulkload,
             List<List<AlgebricksPipeline>> secondaryKeysPipelines, IOperatorSchema pipelineTopSchema)
@@ -132,42 +119,28 @@
      * Creates the delete runtime of IndexInsertDeletePOperator, which models
      * insert/delete operations into a secondary index.
      *
-     * @param dataSource
-     *            Target secondary index.
-     * @param propagatedSchema
-     *            Output schema of the insert/delete operator to be created.
-     * @param inputSchemas
-     *            Output schemas of the insert/delete operator to be created.
-     * @param typeEnv
-     *            Type environment of the original IndexInsertDeleteOperator operator.
-     * @param primaryKeys
-     *            Variables for the dataset's primary keys that the dataSource secondary index belongs to.
-     * @param secondaryKeys
-     *            Variables for the secondary-index keys.
-     * @param additionalNonKeyFields
-     *            Additional variables that can be passed to the secondary index as payload.
-     *            This can be useful when creating a second filter on a non-primary and non-secondary
-     *            fields for additional pruning power.
-     * @param filterExpr
-     *            Filtering expression to be pushed inside the runtime op.
-     *            Such a filter may, e.g., exclude NULLs from being inserted/deleted.
-     * @param recordDesc
-     *            Output record descriptor of the runtime op to be created.
-     * @param context
-     *            Job generation context.
-     * @param spec
-     *            Target job specification.
-     * @param secondaryKeysPipelines
-     *            Nested plan to extract secondary keys.
-     * @param pipelineTopSchema
-     *            Schema of the primary pipeline for secondary keys.
-     * @return
-     *         A Hyracks IOperatorDescriptor and its partition constraint.
+     * @param dataSource             Target secondary index.
+     * @param propagatedSchema       Output schema of the insert/delete operator to be created.
+     * @param inputSchemas           Output schemas of the insert/delete operator to be created.
+     * @param typeEnv                Type environment of the original IndexInsertDeleteOperator operator.
+     * @param primaryKeys            Variables for the dataset's primary keys that the dataSource secondary index belongs to.
+     * @param secondaryKeys          Variables for the secondary-index keys.
+     * @param additionalNonKeyFields Additional variables that can be passed to the secondary index as payload.
+     *                               This can be useful when creating a second filter on a non-primary and non-secondary
+     *                               fields for additional pruning power.
+     * @param filterExpr             Filtering expression to be pushed inside the runtime op.
+     *                               Such a filter may, e.g., exclude NULLs from being inserted/deleted.
+     * @param recordDesc             Output record descriptor of the runtime op to be created.
+     * @param context                Job generation context.
+     * @param spec                   Target job specification.
+     * @param secondaryKeysPipelines Nested plan to extract secondary keys.
+     * @param pipelineTopSchema      Schema of the primary pipeline for secondary keys.
+     * @return A Hyracks IOperatorDescriptor and its partition constraint.
      * @throws AlgebricksException
      */
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getIndexDeleteRuntime(
-            IDataSourceIndex<I, S> dataSource, IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas,
-            IVariableTypeEnvironment typeEnv, List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getIndexDeleteRuntime(IDataSourceIndex<I, S> dataSource,
+            IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas, IVariableTypeEnvironment typeEnv,
+            List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys,
             List<LogicalVariable> additionalNonKeyFields, ILogicalExpression filterExpr, RecordDescriptor recordDesc,
             JobGenContext context, JobSpecification spec, List<List<AlgebricksPipeline>> secondaryKeysPipelines,
             IOperatorSchema pipelineTopSchema) throws AlgebricksException;
@@ -177,48 +150,37 @@
      * secondary key into [token, number of token] pair in a length-partitioned index.
      * In case of non length-partitioned index, it tokenizes secondary key into [token].
      *
-     * @param dataSource
-     *            Target secondary index.
-     * @param propagatedSchema
-     *            Output schema of the insert/delete operator to be created.
-     * @param inputSchemas
-     *            Output schemas of the insert/delete operator to be created.
-     * @param typeEnv
-     *            Type environment of the original IndexInsertDeleteOperator operator.
-     * @param primaryKeys
-     *            Variables for the dataset's primary keys that the dataSource secondary index belongs to.
-     * @param secondaryKeys
-     *            Variables for the secondary-index keys.
-     * @param filterExpr
-     *            Filtering expression to be pushed inside the runtime op.
-     *            Such a filter may, e.g., exclude NULLs from being inserted/deleted.
-     * @param recordDesc
-     *            Output record descriptor of the runtime op to be created.
-     * @param context
-     *            Job generation context.
-     * @param spec
-     *            Target job specification.
-     * @return
-     *         A Hyracks IOperatorDescriptor and its partition constraint.
+     * @param dataSource       Target secondary index.
+     * @param propagatedSchema Output schema of the insert/delete operator to be created.
+     * @param inputSchemas     Output schemas of the insert/delete operator to be created.
+     * @param typeEnv          Type environment of the original IndexInsertDeleteOperator operator.
+     * @param primaryKeys      Variables for the dataset's primary keys that the dataSource secondary index belongs to.
+     * @param secondaryKeys    Variables for the secondary-index keys.
+     * @param filterExpr       Filtering expression to be pushed inside the runtime op.
+     *                         Such a filter may, e.g., exclude NULLs from being inserted/deleted.
+     * @param recordDesc       Output record descriptor of the runtime op to be created.
+     * @param context          Job generation context.
+     * @param spec             Target job specification.
+     * @return A Hyracks IOperatorDescriptor and its partition constraint.
      * @throws AlgebricksException
      */
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getTokenizerRuntime(
-            IDataSourceIndex<I, S> dataSource, IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas,
-            IVariableTypeEnvironment typeEnv, List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys,
-            ILogicalExpression filterExpr, RecordDescriptor recordDesc, JobGenContext context, JobSpecification spec,
-            boolean bulkload) throws AlgebricksException;
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getTokenizerRuntime(IDataSourceIndex<I, S> dataSource,
+            IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas, IVariableTypeEnvironment typeEnv,
+            List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys, ILogicalExpression filterExpr,
+            RecordDescriptor recordDesc, JobGenContext context, JobSpecification spec, boolean bulkload)
+            throws AlgebricksException;
 
-    public IDataSourceIndex<I, S> findDataSourceIndex(I indexId, S dataSourceId) throws AlgebricksException;
+    IDataSourceIndex<I, S> findDataSourceIndex(I indexId, S dataSourceId) throws AlgebricksException;
 
-    public IFunctionInfo lookupFunction(FunctionIdentifier fid);
+    IFunctionInfo lookupFunction(FunctionIdentifier fid);
 
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getUpsertRuntime(IDataSource<S> dataSource,
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getUpsertRuntime(IDataSource<S> dataSource,
             IOperatorSchema inputSchema, IVariableTypeEnvironment typeEnv, List<LogicalVariable> keys,
             LogicalVariable payLoadVar, List<LogicalVariable> additionalFilterFields,
             List<LogicalVariable> additionalNonFilteringFields, RecordDescriptor recordDesc, JobGenContext context,
             JobSpecification jobSpec) throws AlgebricksException;
 
-    public Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getIndexUpsertRuntime(
+    Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> getIndexUpsertRuntime(
             IDataSourceIndex<I, S> dataSourceIndex, IOperatorSchema propagatedSchema, IOperatorSchema[] inputSchemas,
             IVariableTypeEnvironment typeEnv, List<LogicalVariable> primaryKeys, List<LogicalVariable> secondaryKeys,
             List<LogicalVariable> additionalFilteringKeys, ILogicalExpression filterExpr,
@@ -226,12 +188,11 @@
             LogicalVariable prevAdditionalFilteringKeys, RecordDescriptor inputDesc, JobGenContext context,
             JobSpecification spec, List<List<AlgebricksPipeline>> secondaryKeysPipelines) throws AlgebricksException;
 
-    public ITupleFilterFactory createTupleFilterFactory(IOperatorSchema[] inputSchemas,
-            IVariableTypeEnvironment typeEnv, ILogicalExpression filterExpr, JobGenContext context)
-            throws AlgebricksException;
+    ITupleFilterFactory createTupleFilterFactory(IOperatorSchema[] inputSchemas, IVariableTypeEnvironment typeEnv,
+            ILogicalExpression filterExpr, JobGenContext context) throws AlgebricksException;
 
-    public Map<String, Object> getConfig();
+    Map<String, Object> getConfig();
 
-    public boolean isBlockingOperatorDisabled();
+    boolean isBlockingOperatorDisabled();
 
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IProjectionInfo.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IProjectionFiltrationInfo.java
similarity index 80%
rename from hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IProjectionInfo.java
rename to hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IProjectionFiltrationInfo.java
index 3c1a24d..9973d08 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IProjectionInfo.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IProjectionFiltrationInfo.java
@@ -18,18 +18,22 @@
  */
 package org.apache.hyracks.algebricks.core.algebra.metadata;
 
+import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+
 /**
  * Generic interface to include the projection information for
  * {@link org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator}
  */
-public interface IProjectionInfo<T> {
+public interface IProjectionFiltrationInfo<T> {
     /**
      * @return projected values' information
      */
     T getProjectionInfo();
 
+    ILogicalExpression getFilterExpression();
+
     /**
-     * @return a copy of the {@link IProjectionInfo}
+     * @return a copy of the {@link IProjectionFiltrationInfo}
      */
-    IProjectionInfo<T> createCopy();
+    IProjectionFiltrationInfo<T> createCopy();
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/DataSourceScanOperator.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/DataSourceScanOperator.java
index 9f73113..e3ce82d 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/DataSourceScanOperator.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/DataSourceScanOperator.java
@@ -29,7 +29,7 @@
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import org.apache.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
 import org.apache.hyracks.algebricks.core.algebra.metadata.IDataSource;
-import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionInfo;
+import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionFiltrationInfo;
 import org.apache.hyracks.algebricks.core.algebra.properties.VariablePropagationPolicy;
 import org.apache.hyracks.algebricks.core.algebra.typing.ITypingContext;
 import org.apache.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionReferenceTransform;
@@ -50,19 +50,22 @@
     // the maximum of number of results output by this operator
     private long outputLimit = -1;
 
-    private IProjectionInfo<?> projectionInfo;
+    private IProjectionFiltrationInfo<?> datasetProjectionInfo;
+    private IProjectionFiltrationInfo<?> metaProjectionInfo;
 
     public DataSourceScanOperator(List<LogicalVariable> variables, IDataSource<?> dataSource) {
-        this(variables, dataSource, null, -1, null);
+        this(variables, dataSource, null, -1, null, null);
     }
 
     public DataSourceScanOperator(List<LogicalVariable> variables, IDataSource<?> dataSource,
-            Mutable<ILogicalExpression> selectCondition, long outputLimit, IProjectionInfo<?> projectionInfo) {
+            Mutable<ILogicalExpression> selectCondition, long outputLimit,
+            IProjectionFiltrationInfo<?> datasetProjectionInfo, IProjectionFiltrationInfo<?> metaProjectionInfo) {
         super(variables, dataSource);
         projectVars = new ArrayList<>();
         this.selectCondition = selectCondition;
         this.outputLimit = outputLimit;
-        this.projectionInfo = projectionInfo;
+        this.datasetProjectionInfo = datasetProjectionInfo;
+        this.metaProjectionInfo = metaProjectionInfo;
     }
 
     @Override
@@ -173,11 +176,19 @@
         this.outputLimit = outputLimit;
     }
 
-    public void setProjectionInfo(IProjectionInfo<?> projectionInfo) {
-        this.projectionInfo = projectionInfo;
+    public void setDatasetProjectionInfo(IProjectionFiltrationInfo<?> datasetProjectionInfo) {
+        this.datasetProjectionInfo = datasetProjectionInfo;
     }
 
-    public IProjectionInfo<?> getProjectionInfo() {
-        return projectionInfo;
+    public IProjectionFiltrationInfo<?> getDatasetProjectionInfo() {
+        return datasetProjectionInfo;
+    }
+
+    public void setMetaProjectionInfo(IProjectionFiltrationInfo<?> metaProjectionInfo) {
+        this.metaProjectionInfo = metaProjectionInfo;
+    }
+
+    public IProjectionFiltrationInfo<?> getMetaProjectionInfo() {
+        return metaProjectionInfo;
     }
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/UnnestMapOperator.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/UnnestMapOperator.java
index f8d07b8..6d11931 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/UnnestMapOperator.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/UnnestMapOperator.java
@@ -26,6 +26,7 @@
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import org.apache.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
+import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionFiltrationInfo;
 import org.apache.hyracks.algebricks.core.algebra.typing.ITypingContext;
 import org.apache.hyracks.algebricks.core.algebra.typing.NonPropagatingTypeEnvironment;
 import org.apache.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionReferenceTransform;
@@ -39,14 +40,18 @@
     // the maximum of number of results output by this operator
     private long outputLimit = -1;
 
+    private IProjectionFiltrationInfo<?> datasetProjectionInfo;
+    private IProjectionFiltrationInfo<?> metaProjectionInfo;
+
     public UnnestMapOperator(List<LogicalVariable> variables, Mutable<ILogicalExpression> expression,
             List<Object> variableTypes, boolean propagateInput) {
-        this(variables, expression, variableTypes, propagateInput, null, -1);
+        this(variables, expression, variableTypes, propagateInput, null, -1, null, null);
     }
 
     public UnnestMapOperator(List<LogicalVariable> variables, Mutable<ILogicalExpression> expression,
             List<Object> variableTypes, boolean propagateInput, Mutable<ILogicalExpression> selectCondition,
-            long outputLimit) {
+            long outputLimit, IProjectionFiltrationInfo<?> datasetProjectionInfo,
+            IProjectionFiltrationInfo<?> metaProjectionInfo) {
         super(variables, expression, variableTypes, propagateInput);
         this.selectCondition = selectCondition;
         this.outputLimit = outputLimit;
@@ -101,4 +106,20 @@
         this.outputLimit = outputLimit;
     }
 
+    public void setDatasetProjectionInfo(IProjectionFiltrationInfo<?> projectionInfo) {
+        this.datasetProjectionInfo = projectionInfo;
+    }
+
+    public IProjectionFiltrationInfo<?> getDatasetProjectionInfo() {
+        return datasetProjectionInfo;
+    }
+
+    public void setMetaProjectionInfo(IProjectionFiltrationInfo<?> metaProjectionInfo) {
+        this.metaProjectionInfo = metaProjectionInfo;
+    }
+
+    public IProjectionFiltrationInfo<?> getMetaProjectionInfo() {
+        return metaProjectionInfo;
+    }
+
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java
index cfae695..5a6574a 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java
@@ -447,7 +447,9 @@
         if (!isomorphic) {
             return Boolean.FALSE;
         }
-        isomorphic = op.getExpressionRef().getValue().equals(unnestOpArg.getExpressionRef().getValue());
+        isomorphic = op.getExpressionRef().getValue().equals(unnestOpArg.getExpressionRef().getValue())
+                && Objects.equals(op.getDatasetProjectionInfo(), unnestOpArg.getDatasetProjectionInfo())
+                && Objects.equals(op.getMetaProjectionInfo(), unnestOpArg.getMetaProjectionInfo());
         return isomorphic;
     }
 
@@ -480,7 +482,8 @@
         DataSourceScanOperator argScan = (DataSourceScanOperator) arg;
         boolean isomorphic = op.getDataSource().getId().equals(argScan.getDataSource().getId())
                 && op.getOutputLimit() == argScan.getOutputLimit()
-                && Objects.equals(op.getProjectionInfo(), argScan.getProjectionInfo());
+                && Objects.equals(op.getDatasetProjectionInfo(), argScan.getDatasetProjectionInfo())
+                && Objects.equals(op.getMetaProjectionInfo(), argScan.getMetaProjectionInfo());
 
         if (!isomorphic) {
             return Boolean.FALSE;
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java
index 08acf13..71a659b 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java
@@ -37,7 +37,7 @@
 import org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext;
 import org.apache.hyracks.algebricks.core.algebra.base.IVariableContext;
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionInfo;
+import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionFiltrationInfo;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
@@ -104,22 +104,17 @@
     private final boolean reuseFreeVars;
 
     /**
-     * @param varContext
-     *            , the variable context.
-     * @param typeContext
-     *            the type context.
+     * @param varContext  , the variable context.
+     * @param typeContext the type context.
      */
     public LogicalOperatorDeepCopyWithNewVariablesVisitor(IVariableContext varContext, ITypingContext typeContext) {
         this(varContext, typeContext, new LinkedHashMap<>(), false);
     }
 
     /**
-     * @param varContext
-     *            , the variable context.
-     * @param typeContext
-     *            the type context.
-     * @param reuseFreeVars
-     *            whether free variables in the given plan tree should be reused.
+     * @param varContext    , the variable context.
+     * @param typeContext   the type context.
+     * @param reuseFreeVars whether free variables in the given plan tree should be reused.
      */
     public LogicalOperatorDeepCopyWithNewVariablesVisitor(IVariableContext varContext, ITypingContext typeContext,
             boolean reuseFreeVars) {
@@ -127,16 +122,12 @@
     }
 
     /**
-     * @param varContext
-     *            , the variable context.
-     * @param typeContext
-     *            the type context.
-     * @param inVarMapping
-     *            Variable mapping keyed by variables in the original plan.
-     *            Those variables are replaced by their corresponding value in
-     *            the map in the copied plan.
-     * @param reuseFreeVars
-     *            whether free variables in the given plan tree should be reused.
+     * @param varContext    , the variable context.
+     * @param typeContext   the type context.
+     * @param inVarMapping  Variable mapping keyed by variables in the original plan.
+     *                      Those variables are replaced by their corresponding value in
+     *                      the map in the copied plan.
+     * @param reuseFreeVars whether free variables in the given plan tree should be reused.
      */
     public LogicalOperatorDeepCopyWithNewVariablesVisitor(IVariableContext varContext, ITypingContext typeContext,
             LinkedHashMap<LogicalVariable, LogicalVariable> inVarMapping, boolean reuseFreeVars) {
@@ -326,9 +317,12 @@
             throws AlgebricksException {
         Mutable<ILogicalExpression> newSelectCondition = op.getSelectCondition() != null
                 ? exprDeepCopyVisitor.deepCopyExpressionReference(op.getSelectCondition()) : null;
-        IProjectionInfo<?> projectionInfo = op.getProjectionInfo() != null ? op.getProjectionInfo().createCopy() : null;
+        IProjectionFiltrationInfo<?> datasetProjectionInfo =
+                op.getDatasetProjectionInfo() != null ? op.getDatasetProjectionInfo().createCopy() : null;
+        IProjectionFiltrationInfo<?> metaProjectionInfo =
+                op.getMetaProjectionInfo() != null ? op.getMetaProjectionInfo().createCopy() : null;
         DataSourceScanOperator opCopy = new DataSourceScanOperator(deepCopyVariableList(op.getVariables()),
-                op.getDataSource(), newSelectCondition, op.getOutputLimit(), projectionInfo);
+                op.getDataSource(), newSelectCondition, op.getOutputLimit(), datasetProjectionInfo, metaProjectionInfo);
         deepCopyInputsAnnotationsAndExecutionMode(op, arg, opCopy);
         return opCopy;
     }
@@ -540,9 +534,14 @@
             throws AlgebricksException {
         Mutable<ILogicalExpression> newSelectCondition = op.getSelectCondition() != null
                 ? exprDeepCopyVisitor.deepCopyExpressionReference(op.getSelectCondition()) : null;
+        IProjectionFiltrationInfo<?> datasetProjectionInfo =
+                op.getDatasetProjectionInfo() != null ? op.getDatasetProjectionInfo().createCopy() : null;
+        IProjectionFiltrationInfo<?> metaProjectionInfo =
+                op.getMetaProjectionInfo() != null ? op.getMetaProjectionInfo().createCopy() : null;
         UnnestMapOperator opCopy = new UnnestMapOperator(deepCopyVariableList(op.getVariables()),
                 exprDeepCopyVisitor.deepCopyExpressionReference(op.getExpressionRef()), op.getVariableTypes(),
-                op.propagatesInput(), newSelectCondition, op.getOutputLimit());
+                op.propagatesInput(), newSelectCondition, op.getOutputLimit(), datasetProjectionInfo,
+                metaProjectionInfo);
         deepCopyInputsAnnotationsAndExecutionMode(op, arg, opCopy);
         return opCopy;
     }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/OperatorDeepCopyVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/OperatorDeepCopyVisitor.java
index 8ef0b5b..b7029d1 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/OperatorDeepCopyVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/OperatorDeepCopyVisitor.java
@@ -33,7 +33,7 @@
 import org.apache.hyracks.algebricks.core.algebra.base.ILogicalPlan;
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import org.apache.hyracks.algebricks.core.algebra.expressions.AbstractLogicalExpression;
-import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionInfo;
+import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionFiltrationInfo;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator;
@@ -245,8 +245,13 @@
         newInputList.addAll(op.getVariables());
         Mutable<ILogicalExpression> newSelectCondition =
                 op.getSelectCondition() != null ? deepCopyExpressionRef(op.getSelectCondition()) : null;
+        IProjectionFiltrationInfo<?> datasetProjectionInfo =
+                op.getDatasetProjectionInfo() != null ? op.getDatasetProjectionInfo().createCopy() : null;
+        IProjectionFiltrationInfo<?> metaProjectionInfo =
+                op.getMetaProjectionInfo() != null ? op.getMetaProjectionInfo().createCopy() : null;
         return new UnnestMapOperator(newInputList, deepCopyExpressionRef(op.getExpressionRef()),
-                new ArrayList<>(op.getVariableTypes()), op.propagatesInput(), newSelectCondition, op.getOutputLimit());
+                new ArrayList<>(op.getVariableTypes()), op.propagatesInput(), newSelectCondition, op.getOutputLimit(),
+                datasetProjectionInfo, metaProjectionInfo);
     }
 
     @Override
@@ -264,10 +269,13 @@
         newInputList.addAll(op.getVariables());
         Mutable<ILogicalExpression> newSelectCondition =
                 op.getSelectCondition() != null ? deepCopyExpressionRef(op.getSelectCondition()) : null;
-        IProjectionInfo<?> projectionInfo = op.getProjectionInfo() != null ? op.getProjectionInfo().createCopy() : null;
+        IProjectionFiltrationInfo<?> datasetProjectionInfo =
+                op.getDatasetProjectionInfo() != null ? op.getDatasetProjectionInfo().createCopy() : null;
+        IProjectionFiltrationInfo<?> metaProjectionInfo =
+                op.getMetaProjectionInfo() != null ? op.getMetaProjectionInfo().createCopy() : null;
 
         return new DataSourceScanOperator(newInputList, op.getDataSource(), newSelectCondition, op.getOutputLimit(),
-                projectionInfo);
+                datasetProjectionInfo, metaProjectionInfo);
     }
 
     @Override
@@ -379,7 +387,7 @@
     private void deepCopyExpressionRefs(List<Mutable<ILogicalExpression>> newExprs,
             List<Mutable<ILogicalExpression>> oldExprs) {
         for (Mutable<ILogicalExpression> oldExpr : oldExprs) {
-            newExprs.add(new MutableObject<>(((AbstractLogicalExpression) oldExpr.getValue()).cloneExpression()));
+            newExprs.add(new MutableObject<>(oldExpr.getValue().cloneExpression()));
         }
     }
 
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/physical/DataSourceScanPOperator.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/physical/DataSourceScanPOperator.java
index 48dc607..866334a 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/physical/DataSourceScanPOperator.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/physical/DataSourceScanPOperator.java
@@ -116,10 +116,10 @@
                     scan.getSelectCondition().getValue(), context);
         }
 
-        Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> p =
-                mp.getScannerRuntime(dataSource, vars, projectVars, scan.isProjectPushed(), scan.getMinFilterVars(),
-                        scan.getMaxFilterVars(), tupleFilterFactory, scan.getOutputLimit(), opSchema, typeEnv, context,
-                        builder.getJobSpec(), implConfig, scan.getProjectionInfo());
+        Pair<IOperatorDescriptor, AlgebricksPartitionConstraint> p = mp.getScannerRuntime(dataSource, vars, projectVars,
+                scan.isProjectPushed(), scan.getMinFilterVars(), scan.getMaxFilterVars(), tupleFilterFactory,
+                scan.getOutputLimit(), opSchema, typeEnv, context, builder.getJobSpec(), implConfig,
+                scan.getDatasetProjectionInfo(), scan.getMetaProjectionInfo());
         IOperatorDescriptor opDesc = p.first;
         opDesc.setSourceLocation(scan.getSourceLocation());
         builder.contributeHyracksOperator(scan, opDesc);
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java
index 7aabbef..069012b 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java
@@ -33,7 +33,7 @@
 import org.apache.hyracks.algebricks.core.algebra.base.IPhysicalOperator;
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import org.apache.hyracks.algebricks.core.algebra.expressions.IAlgebricksConstantValue;
-import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionInfo;
+import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionFiltrationInfo;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractOperatorWithNestedPlans;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractUnnestMapOperator;
@@ -359,6 +359,9 @@
         AlgebricksStringBuilderWriter plan = printAbstractUnnestMapOperator(op, indent, "unnest-map", null);
         appendSelectConditionInformation(plan, op.getSelectCondition(), indent);
         appendLimitInformation(plan, op.getOutputLimit());
+        appendProjectInformation(plan, "project", op.getDatasetProjectionInfo());
+        appendProjectInformation(plan, "project-meta", op.getMetaProjectionInfo());
+        appendFilterExpression(plan, op.getDatasetProjectionInfo());
         return null;
     }
 
@@ -386,7 +389,9 @@
         appendFilterInformation(plan, op.getMinFilterVars(), op.getMaxFilterVars());
         appendSelectConditionInformation(plan, op.getSelectCondition(), indent);
         appendLimitInformation(plan, op.getOutputLimit());
-        appendProjectInformation(plan, op.getProjectionInfo());
+        appendProjectInformation(plan, "project", op.getDatasetProjectionInfo());
+        appendProjectInformation(plan, "project-meta", op.getMetaProjectionInfo());
+        appendFilterExpression(plan, op.getDatasetProjectionInfo());
         return null;
     }
 
@@ -417,15 +422,30 @@
         }
     }
 
-    private void appendProjectInformation(AlgebricksStringBuilderWriter plan, IProjectionInfo<?> projectionInfo) {
+    private void appendProjectInformation(AlgebricksStringBuilderWriter plan, String projectionSource,
+            IProjectionFiltrationInfo<?> projectionInfo) {
         final String projectedFields = projectionInfo == null ? "" : projectionInfo.toString();
         if (!projectedFields.isEmpty()) {
-            plan.append(" project (");
+            plan.append(" ");
+            plan.append(projectionSource);
+            plan.append(" (");
             plan.append(projectedFields);
             plan.append(")");
         }
     }
 
+    private void appendFilterExpression(AlgebricksStringBuilderWriter plan,
+            IProjectionFiltrationInfo<?> projectionInfo) {
+        final String filterExpr = projectionInfo == null || projectionInfo.getFilterExpression() == null ? ""
+                : projectionInfo.getFilterExpression().toString();
+        if (!filterExpr.isEmpty()) {
+            plan.append(" filter on ");
+            plan.append("(");
+            plan.append(filterExpr);
+            plan.append(")");
+        }
+    }
+
     @Override
     public Void visitLimitOperator(LimitOperator op, Integer indent) throws AlgebricksException {
         addIndent(indent).append("limit");
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitorJson.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitorJson.java
index e54ef02..115448e 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitorJson.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitorJson.java
@@ -38,7 +38,7 @@
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import org.apache.hyracks.algebricks.core.algebra.base.PhysicalOperatorTag;
 import org.apache.hyracks.algebricks.core.algebra.expressions.IAlgebricksConstantValue;
-import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionInfo;
+import org.apache.hyracks.algebricks.core.algebra.metadata.IProjectionFiltrationInfo;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractBinaryJoinOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractOperatorWithNestedPlans;
@@ -545,6 +545,9 @@
         try {
             writeUnnestMapOperator(op, indent, "unnest-map", null);
             writeSelectLimitInformation(op.getSelectCondition(), op.getOutputLimit(), indent);
+            writeProjectInformation("project", op.getDatasetProjectionInfo());
+            writeProjectInformation("project-meta", op.getMetaProjectionInfo());
+            writeFilterInformation(op.getDatasetProjectionInfo());
             return null;
         } catch (IOException e) {
             throw AlgebricksException.create(ErrorCode.ERROR_PRINTING_PLAN, e, String.valueOf(e));
@@ -574,7 +577,9 @@
             }
             writeFilterInformation(op.getMinFilterVars(), op.getMaxFilterVars());
             writeSelectLimitInformation(op.getSelectCondition(), op.getOutputLimit(), indent);
-            writeProjectInformation(op.getProjectionInfo());
+            writeProjectInformation("project", op.getDatasetProjectionInfo());
+            writeProjectInformation("project-meta", op.getMetaProjectionInfo());
+            writeFilterInformation(op.getDatasetProjectionInfo());
             return null;
         } catch (IOException e) {
             throw AlgebricksException.create(ErrorCode.ERROR_PRINTING_PLAN, e, String.valueOf(e));
@@ -903,10 +908,19 @@
         }
     }
 
-    private void writeProjectInformation(IProjectionInfo<?> projectionInfo) throws IOException {
+    private void writeProjectInformation(String projectionSource, IProjectionFiltrationInfo<?> projectionInfo)
+            throws IOException {
         final String projectedFields = projectionInfo == null ? "" : projectionInfo.toString();
         if (!projectedFields.isEmpty()) {
-            jsonGenerator.writeStringField("project", projectedFields);
+            jsonGenerator.writeStringField(projectionSource, projectedFields);
+        }
+    }
+
+    private void writeFilterInformation(IProjectionFiltrationInfo<?> projectionInfo) throws IOException {
+        final String filterExpr = projectionInfo == null || projectionInfo.getFilterExpression() == null ? ""
+                : projectionInfo.getFilterExpression().toString();
+        if (!filterExpr.isEmpty()) {
+            jsonGenerator.writeStringField("filter-on", filterExpr);
         }
     }
 
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/config/AlgebricksConfig.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/config/AlgebricksConfig.java
index c94d72a..0d02203 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/config/AlgebricksConfig.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/config/AlgebricksConfig.java
@@ -45,4 +45,5 @@
     public static final int EXTERNAL_SCAN_BUFFER_SIZE =
             StorageUtil.getIntSizeInBytes(8, StorageUtil.StorageUnit.KILOBYTE);
     public static final boolean BATCH_LOOKUP_DEFAULT = false;
+    public static final boolean COLUMN_FILTER_DEFAULT = false;
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/rewriter/base/PhysicalOptimizationConfig.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/rewriter/base/PhysicalOptimizationConfig.java
index 86be6d0..3e51a80 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/rewriter/base/PhysicalOptimizationConfig.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/rewriter/base/PhysicalOptimizationConfig.java
@@ -52,6 +52,7 @@
     private static final String CBO_TEST = "CBO_TEST";
     private static final String FORCE_JOIN_ORDER = "FORCE_JOIN_ORDER";
     private static final String QUERY_PLAN_SHAPE = "QUERY_PLAN_SHAPE";
+    private static final String COLUMN_FILTER = "COLUMN_FILTER";
 
     private final Properties properties = new Properties();
 
@@ -294,6 +295,14 @@
         setInt(EXTERNAL_SCAN_BUFFER_SIZE, bufferSize);
     }
 
+    public void setColumnFilter(boolean columnFilter) {
+        setBoolean(COLUMN_FILTER, columnFilter);
+    }
+
+    public boolean isColumnFilterEnabled() {
+        return getBoolean(COLUMN_FILTER, AlgebricksConfig.COLUMN_FILTER_DEFAULT);
+    }
+
     private void setInt(String property, int value) {
         properties.setProperty(property, Integer.toString(value));
     }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java b/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java
index d555b31..4fc8057 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java
@@ -243,12 +243,6 @@
             cursor.next();
             matchingTupleCount++;
             ITupleReference tuple = cursor.getTuple();
-            if (tupleFilter != null) {
-                referenceFilterTuple.reset(tuple);
-                if (!tupleFilter.accept(referenceFilterTuple)) {
-                    continue;
-                }
-            }
             tb.reset();
 
             if (retainInput) {
@@ -258,7 +252,17 @@
                     tb.addFieldEndOffset();
                 }
             }
-            writeTupleToOutput(tuple);
+
+            // tuple must be written first before the filter is applied to
+            // assemble columnar tuples
+            tuple = writeTupleToOutput(tuple);
+            if (tupleFilter != null) {
+                referenceFilterTuple.reset(tuple);
+                if (!tupleFilter.accept(referenceFilterTuple)) {
+                    continue;
+                }
+            }
+
             if (appendSearchCallbackProceedResult) {
                 writeSearchCallbackProceedResult(tb,
                         ((ILSMIndexCursor) cursor).getSearchOperationCallbackProceedResult());
@@ -355,9 +359,9 @@
         }
     }
 
-    protected void writeTupleToOutput(ITupleReference tuple) throws IOException {
+    protected ITupleReference writeTupleToOutput(ITupleReference tuple) throws IOException {
         try {
-            tupleProjector.project(tuple, dos, tb);
+            return tupleProjector.project(tuple, dos, tb);
         } catch (Exception e) {
             throw e;
         }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/pom.xml b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/pom.xml
index cadc714..8e0bc0c 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/pom.xml
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/pom.xml
@@ -91,5 +91,9 @@
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-api</artifactId>
     </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+    </dependency>
   </dependencies>
 </project>
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/dataflow/LSMColumnBTreeLocalResource.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/dataflow/LSMColumnBTreeLocalResource.java
new file mode 100644
index 0000000..56090bb
--- /dev/null
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/dataflow/LSMColumnBTreeLocalResource.java
@@ -0,0 +1,125 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hyracks.storage.am.lsm.btree.column.dataflow;
+
+import java.util.List;
+import java.util.Map;
+
+import org.apache.hyracks.api.application.INCServiceContext;
+import org.apache.hyracks.api.compression.ICompressorDecompressorFactory;
+import org.apache.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import org.apache.hyracks.api.dataflow.value.ITypeTraits;
+import org.apache.hyracks.api.exceptions.HyracksDataException;
+import org.apache.hyracks.api.io.FileReference;
+import org.apache.hyracks.api.io.IIOManager;
+import org.apache.hyracks.api.io.IJsonSerializable;
+import org.apache.hyracks.api.io.IPersistedResourceRegistry;
+import org.apache.hyracks.storage.am.common.api.IMetadataPageManagerFactory;
+import org.apache.hyracks.storage.am.common.api.INullIntrospector;
+import org.apache.hyracks.storage.am.lsm.btree.column.api.IColumnManagerFactory;
+import org.apache.hyracks.storage.am.lsm.btree.column.utils.LSMColumnBTreeUtil;
+import org.apache.hyracks.storage.am.lsm.btree.dataflow.LSMBTreeLocalResource;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMMergePolicyFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMPageWriteCallbackFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import org.apache.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
+import org.apache.hyracks.storage.common.IStorageManager;
+import org.apache.hyracks.storage.common.compression.NoOpCompressorDecompressorFactory;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+public class LSMColumnBTreeLocalResource extends LSMBTreeLocalResource {
+    private final IColumnManagerFactory columnManagerFactory;
+
+    public LSMColumnBTreeLocalResource(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories,
+            int[] bloomFilterKeyFields, double bloomFilterFalsePositiveRate, String path,
+            IStorageManager storageManager, ILSMMergePolicyFactory mergePolicyFactory,
+            Map<String, String> mergePolicyProperties, int[] btreeFields, ILSMOperationTrackerFactory opTrackerProvider,
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory, ILSMPageWriteCallbackFactory pageWriteCallbackFactory,
+            IMetadataPageManagerFactory metadataPageManagerFactory, IVirtualBufferCacheProvider vbcProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider,
+            ICompressorDecompressorFactory compressorDecompressorFactory, ITypeTraits nullTypeTraits,
+            INullIntrospector nullIntrospector, boolean isSecondaryNoIncrementalMaintenance,
+            IColumnManagerFactory columnManagerFactory) {
+        super(typeTraits, cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate, true, path, storageManager,
+                mergePolicyFactory, mergePolicyProperties, null, null, btreeFields, null, opTrackerProvider,
+                ioOpCallbackFactory, pageWriteCallbackFactory, metadataPageManagerFactory, vbcProvider,
+                ioSchedulerProvider, true, compressorDecompressorFactory, true, nullTypeTraits, nullIntrospector,
+                isSecondaryNoIncrementalMaintenance);
+        this.columnManagerFactory = columnManagerFactory;
+    }
+
+    private LSMColumnBTreeLocalResource(IPersistedResourceRegistry registry, JsonNode json, int[] bloomFilterKeyFields,
+            double bloomFilterFalsePositiveRate, boolean isPrimary, int[] btreeFields,
+            ICompressorDecompressorFactory compressorDecompressorFactory, boolean hasBloomFilter,
+            boolean isSecondaryNoIncrementalMaintenance, IColumnManagerFactory columnManagerFactory)
+            throws HyracksDataException {
+        super(registry, json, bloomFilterKeyFields, bloomFilterFalsePositiveRate, isPrimary, btreeFields,
+                compressorDecompressorFactory, hasBloomFilter, isSecondaryNoIncrementalMaintenance);
+        this.columnManagerFactory = columnManagerFactory;
+    }
+
+    @Override
+    public ILSMIndex createInstance(INCServiceContext serviceCtx) throws HyracksDataException {
+        IIOManager ioManager = serviceCtx.getIoManager();
+        FileReference file = ioManager.resolve(path);
+        List<IVirtualBufferCache> vbcs = vbcProvider.getVirtualBufferCaches(serviceCtx, file);
+        ioOpCallbackFactory.initialize(serviceCtx, this);
+        pageWriteCallbackFactory.initialize(serviceCtx, this);
+        return LSMColumnBTreeUtil.createLSMTree(ioManager, vbcs, file, storageManager.getBufferCache(serviceCtx),
+                typeTraits, cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate,
+                mergePolicyFactory.createMergePolicy(mergePolicyProperties, serviceCtx),
+                opTrackerProvider.getOperationTracker(serviceCtx, this), ioSchedulerProvider.getIoScheduler(serviceCtx),
+                ioOpCallbackFactory, pageWriteCallbackFactory, btreeFields, metadataPageManagerFactory, false,
+                serviceCtx.getTracer(), compressorDecompressorFactory, nullTypeTraits, nullIntrospector,
+                columnManagerFactory);
+    }
+
+    public static IJsonSerializable fromJson(IPersistedResourceRegistry registry, JsonNode json)
+            throws HyracksDataException {
+        int[] bloomFilterKeyFields = OBJECT_MAPPER.convertValue(json.get("bloomFilterKeyFields"), int[].class);
+        double bloomFilterFalsePositiveRate = json.get("bloomFilterFalsePositiveRate").asDouble();
+        boolean isPrimary = json.get("isPrimary").asBoolean();
+        boolean hasBloomFilter = getOrDefaultHasBloomFilter(json, isPrimary);
+        int[] btreeFields = OBJECT_MAPPER.convertValue(json.get("btreeFields"), int[].class);
+        JsonNode compressorDecompressorNode = json.get("compressorDecompressorFactory");
+        ICompressorDecompressorFactory compDecompFactory = (ICompressorDecompressorFactory) registry
+                .deserializeOrDefault(compressorDecompressorNode, NoOpCompressorDecompressorFactory.class);
+        JsonNode columnManagerFactoryNode = json.get("columnManagerFactory");
+        boolean isSecondaryNoIncrementalMaintenance =
+                getOrDefaultBoolean(json, "isSecondaryNoIncrementalMaintenance", false);
+        IColumnManagerFactory columnManagerFactory =
+                (IColumnManagerFactory) registry.deserialize(columnManagerFactoryNode);
+        return new LSMColumnBTreeLocalResource(registry, json, bloomFilterKeyFields, bloomFilterFalsePositiveRate,
+                isPrimary, btreeFields, compDecompFactory, hasBloomFilter, isSecondaryNoIncrementalMaintenance,
+                columnManagerFactory);
+    }
+
+    @Override
+    protected void appendToJson(final ObjectNode json, IPersistedResourceRegistry registry)
+            throws HyracksDataException {
+        super.appendToJson(json, registry);
+        json.putPOJO("columnManagerFactory", columnManagerFactory.toJson(registry));
+    }
+}
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/dataflow/LSMColumnBTreeLocalResourceFactory.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/dataflow/LSMColumnBTreeLocalResourceFactory.java
new file mode 100644
index 0000000..eccb7c2
--- /dev/null
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/dataflow/LSMColumnBTreeLocalResourceFactory.java
@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hyracks.storage.am.lsm.btree.column.dataflow;
+
+import java.util.Map;
+
+import org.apache.hyracks.api.compression.ICompressorDecompressorFactory;
+import org.apache.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import org.apache.hyracks.api.dataflow.value.ITypeTraits;
+import org.apache.hyracks.api.io.FileReference;
+import org.apache.hyracks.storage.am.common.api.IMetadataPageManagerFactory;
+import org.apache.hyracks.storage.am.common.api.INullIntrospector;
+import org.apache.hyracks.storage.am.lsm.btree.column.api.IColumnManagerFactory;
+import org.apache.hyracks.storage.am.lsm.btree.dataflow.LSMBTreeLocalResourceFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMMergePolicyFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.ILSMPageWriteCallbackFactory;
+import org.apache.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
+import org.apache.hyracks.storage.am.lsm.common.dataflow.LsmResource;
+import org.apache.hyracks.storage.common.IStorageManager;
+
+public class LSMColumnBTreeLocalResourceFactory extends LSMBTreeLocalResourceFactory {
+    private static final long serialVersionUID = -676367767925618165L;
+    private final IColumnManagerFactory columnManagerFactory;
+
+    public LSMColumnBTreeLocalResourceFactory(IStorageManager storageManager, ITypeTraits[] typeTraits,
+            IBinaryComparatorFactory[] cmpFactories, ITypeTraits[] filterTypeTraits,
+            IBinaryComparatorFactory[] filterCmpFactories, int[] filterFields,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
+            ILSMPageWriteCallbackFactory pageWriteCallbackFactory,
+            IMetadataPageManagerFactory metadataPageManagerFactory, IVirtualBufferCacheProvider vbcProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMMergePolicyFactory mergePolicyFactory,
+            Map<String, String> mergePolicyProperties, int[] bloomFilterKeyFields, double bloomFilterFalsePositiveRate,
+            int[] btreeFields, ICompressorDecompressorFactory compressorDecompressorFactory, ITypeTraits nullTypeTraits,
+            INullIntrospector nullIntrospector, boolean isSecondaryNoIncrementalMaintenance,
+            IColumnManagerFactory columnManagerFactory) {
+        super(storageManager, typeTraits, cmpFactories, filterTypeTraits, filterCmpFactories, filterFields,
+                opTrackerFactory, ioOpCallbackFactory, pageWriteCallbackFactory, metadataPageManagerFactory,
+                vbcProvider, ioSchedulerProvider, mergePolicyFactory, mergePolicyProperties, true, bloomFilterKeyFields,
+                bloomFilterFalsePositiveRate, true, btreeFields, compressorDecompressorFactory, true, nullTypeTraits,
+                nullIntrospector, isSecondaryNoIncrementalMaintenance);
+        this.columnManagerFactory = columnManagerFactory;
+    }
+
+    @Override
+    public LsmResource createResource(FileReference fileRef) {
+        return new LSMColumnBTreeLocalResource(typeTraits, cmpFactories, bloomFilterKeyFields,
+                bloomFilterFalsePositiveRate, fileRef.getRelativePath(), storageManager, mergePolicyFactory,
+                mergePolicyProperties, btreeFields, opTrackerProvider, ioOpCallbackFactory, pageWriteCallbackFactory,
+                metadataPageManagerFactory, vbcProvider, ioSchedulerProvider, compressorDecompressorFactory,
+                nullTypeTraits, nullIntrospector, isSecondaryNoIncrementalMaintenance, columnManagerFactory);
+    }
+}
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/impls/lsm/tuples/AbstractColumnTupleReference.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/impls/lsm/tuples/AbstractColumnTupleReference.java
index d39f94e..d0e1e1d 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/impls/lsm/tuples/AbstractColumnTupleReference.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree-column/src/main/java/org/apache/hyracks/storage/am/lsm/btree/column/impls/lsm/tuples/AbstractColumnTupleReference.java
@@ -40,8 +40,8 @@
     private final IColumnBufferProvider[] primaryKeyBufferProviders;
     private final IColumnBufferProvider[] buffersProviders;
     private final int numberOfPrimaryKeys;
-    private int totalNumberOfPages;
-    private int numOfSkippedPages;
+    private int totalNumberOfMegaLeafNodes;
+    private int numOfSkippedMegaLeafNodes;
     protected int tupleIndex;
 
     /**
@@ -73,8 +73,8 @@
                 buffersProviders[i] = new ColumnSingleBufferProvider(columnIndex);
             }
         }
-        totalNumberOfPages = 0;
-        numOfSkippedPages = 0;
+        totalNumberOfMegaLeafNodes = 0;
+        numOfSkippedMegaLeafNodes = 0;
     }
 
     @Override
@@ -104,9 +104,9 @@
                 startColumn(provider, tupleIndex, i, numberOfTuples);
             }
         } else {
-            numOfSkippedPages++;
+            numOfSkippedMegaLeafNodes++;
         }
-        totalNumberOfPages++;
+        totalNumberOfMegaLeafNodes++;
     }
 
     protected abstract boolean startNewPage(ByteBuffer pageZero, int numberOfColumns, int numberOfTuples);
@@ -149,8 +149,9 @@
 
     @Override
     public final void close() {
-        if (LOGGER.isInfoEnabled()) {
-            LOGGER.info("Skipped {} pages out of {} in total", numOfSkippedPages, totalNumberOfPages);
+        if (LOGGER.isInfoEnabled() && numOfSkippedMegaLeafNodes > 0) {
+            LOGGER.info("Filtered {} disk mega-leaf nodes out of {} in total", numOfSkippedMegaLeafNodes,
+                    totalNumberOfMegaLeafNodes);
         }
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree/src/main/java/org/apache/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeLocalResource.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree/src/main/java/org/apache/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeLocalResource.java
index a7e433c..21c818c 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree/src/main/java/org/apache/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeLocalResource.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-btree/src/main/java/org/apache/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeLocalResource.java
@@ -158,12 +158,12 @@
         json.put("isSecondaryNoIncrementalMaintenance", isSecondaryNoIncrementalMaintenance);
     }
 
-    private static boolean getOrDefaultHasBloomFilter(JsonNode json, boolean isPrimary) {
+    protected static boolean getOrDefaultHasBloomFilter(JsonNode json, boolean isPrimary) {
         // for backward compatibility, only primary indexes have bloom filters
         return getOrDefaultBoolean(json, HAS_BLOOM_FILTER_FIELD, isPrimary);
     }
 
-    private static boolean getOrDefaultBoolean(JsonNode jsonNode, String fieldName, boolean defaultValue) {
+    protected static boolean getOrDefaultBoolean(JsonNode jsonNode, String fieldName, boolean defaultValue) {
         return jsonNode.has(fieldName) ? jsonNode.get(fieldName).asBoolean() : defaultValue;
     }