diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceOrderByAfterSubplan.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceOrderByAfterSubplan.java
index a684bc9..5263213 100644
--- a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceOrderByAfterSubplan.java
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceOrderByAfterSubplan.java
@@ -124,6 +124,11 @@
             /** copy the original order-by operator and insert on-top-of the subplan operator */
             context.addToDontApplySet(this, child);
             OrderOperator sourceOrderOp = (OrderOperator) child;
+            for (Pair<IOrder, Mutable<ILogicalExpression>> expr : sourceOrderOp.getOrderExpressions()) {
+                if (!expr.second.getValue().isFunctional()) {
+                    return false;
+                }
+            }
             List<Pair<IOrder, Mutable<ILogicalExpression>>> orderExprs = deepCopyOrderAndExpression(sourceOrderOp
                     .getOrderExpressions());
             OrderOperator newOrderOp = new OrderOperator(orderExprs);
diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java
index 40b049b..ba62cf6 100644
--- a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/InlineVariablesRule.java
@@ -45,25 +45,20 @@
  * (some variables are generated by datasources).
  * Inlining variables may enable other optimizations by allowing selects and assigns to be moved
  * (e.g., a select may be pushed into a join to enable an efficient physical join operator).
- * 
  * Preconditions/Assumptions:
- * Assumes no projects are in the plan. Only inlines variables whose assigned expression is a function call 
- * (i.e., this rule ignores right-hand side constants and other variable references expressions  
- * 
+ * Assumes no projects are in the plan. Only inlines variables whose assigned expression is a function call
+ * (i.e., this rule ignores right-hand side constants and other variable references expressions
  * Postconditions/Examples:
  * All qualifying variables have been inlined.
- * 
  * Example (simplified):
- * 
  * Before plan:
  * select <- [$$1 < $$2 + $$0]
- *   assign [$$2] <- [funcZ() + $$0]
- *     assign [$$0, $$1] <- [funcX(), funcY()]
- * 
+ * assign [$$2] <- [funcZ() + $$0]
+ * assign [$$0, $$1] <- [funcX(), funcY()]
  * After plan:
  * select <- [funcY() < funcZ() + funcX() + funcX()]
- *   assign [$$2] <- [funcZ() + funcX()]
- *     assign [$$0, $$1] <- [funcX(), funcY()]
+ * assign [$$2] <- [funcZ() + funcX()]
+ * assign [$$0, $$1] <- [funcX(), funcY()]
  */
 public class InlineVariablesRule implements IAlgebraicRewriteRule {
 
@@ -73,12 +68,12 @@
 
     // Visitor for replacing variable reference expressions with their originating expression.
     protected InlineVariablesVisitor inlineVisitor = new InlineVariablesVisitor(varAssignRhs);
-    
+
     // Set of FunctionIdentifiers that we should not inline.
     protected Set<FunctionIdentifier> doNotInlineFuncs = new HashSet<FunctionIdentifier>();
-    
+
     protected boolean hasRun = false;
-    
+
     @Override
     public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) {
         return false;
@@ -100,12 +95,12 @@
         hasRun = true;
         return modified;
     }
-    
+
     protected void prepare(IOptimizationContext context) {
         varAssignRhs.clear();
         inlineVisitor.setContext(context);
     }
-    
+
     protected boolean performBottomUpAction(AbstractLogicalOperator op) throws AlgebricksException {
         // Only inline variables in operators that can deal with arbitrary expressions.
         if (!op.requiresVariableReferenceExpressions()) {
@@ -118,16 +113,16 @@
     protected boolean performFinalAction() throws AlgebricksException {
         return false;
     }
-    
+
     protected boolean inlineVariables(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
             throws AlgebricksException {
         AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
-        
+
         // Update mapping from variables to expressions during top-down traversal.
         if (op.getOperatorTag() == LogicalOperatorTag.ASSIGN) {
             AssignOperator assignOp = (AssignOperator) op;
             List<LogicalVariable> vars = assignOp.getVariables();
-            List<Mutable<ILogicalExpression>> exprs = assignOp.getExpressions();            
+            List<Mutable<ILogicalExpression>> exprs = assignOp.getExpressions();
             for (int i = 0; i < vars.size(); i++) {
                 ILogicalExpression expr = exprs.get(i).getValue();
                 // Ignore functions that are in the doNotInline set.                
@@ -146,13 +141,13 @@
         for (Mutable<ILogicalOperator> inputOpRef : op.getInputs()) {
             if (inlineVariables(inputOpRef, context)) {
                 modified = true;
-            }            
+            }
         }
 
         if (performBottomUpAction(op)) {
             modified = true;
         }
-        
+
         if (modified) {
             context.computeAndSetTypeEnvironmentForOperator(op);
             context.addToDontApplySet(this, op);
@@ -164,23 +159,23 @@
     }
 
     protected class InlineVariablesVisitor implements ILogicalExpressionReferenceTransform {
-        
+
         private final Map<LogicalVariable, ILogicalExpression> varAssignRhs;
         private final Set<LogicalVariable> liveVars = new HashSet<LogicalVariable>();
-        private final List<LogicalVariable> rhsUsedVars = new ArrayList<LogicalVariable>();        
+        private final List<LogicalVariable> rhsUsedVars = new ArrayList<LogicalVariable>();
         private ILogicalOperator op;
         private IOptimizationContext context;
         // If set, only replace this variable reference.
         private LogicalVariable targetVar;
-        
+
         public InlineVariablesVisitor(Map<LogicalVariable, ILogicalExpression> varAssignRhs) {
             this.varAssignRhs = varAssignRhs;
         }
-        
+
         public void setTargetVariable(LogicalVariable targetVar) {
             this.targetVar = targetVar;
         }
-        
+
         public void setContext(IOptimizationContext context) {
             this.context = context;
         }
@@ -189,9 +184,9 @@
             this.op = op;
             liveVars.clear();
         }
-        
+
         @Override
-        public boolean transform(Mutable<ILogicalExpression> exprRef) throws AlgebricksException {            
+        public boolean transform(Mutable<ILogicalExpression> exprRef) throws AlgebricksException {
             ILogicalExpression e = exprRef.getValue();
             switch (((AbstractLogicalExpression) e).getExpressionTag()) {
                 case VARIABLE: {
@@ -209,7 +204,7 @@
                         // Variable was not produced by an assign.
                         return false;
                     }
-                    
+
                     // Make sure used variables from rhs are live.
                     if (liveVars.isEmpty()) {
                         VariableUtilities.getLiveVariables(op, liveVars);
@@ -221,8 +216,11 @@
                             return false;
                         }
                     }
-                    
+
                     // Replace variable reference with a clone of the rhs expr.
+                    if (!rhs.isFunctional()) {
+                        return false;
+                    }
                     exprRef.setValue(rhs.cloneExpression());
                     return true;
                 }
diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushAssignBelowUnionAllRule.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushAssignBelowUnionAllRule.java
index f03f4e3..418ee36 100644
--- a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushAssignBelowUnionAllRule.java
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushAssignBelowUnionAllRule.java
@@ -36,31 +36,28 @@
 import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
 
 /**
- * Pushes an AssignOperator below a UnionAll operator by creating an new AssignOperator below each of 
+ * Pushes an AssignOperator below a UnionAll operator by creating an new AssignOperator below each of
  * the UnionAllOperator's branches with appropriate variable replacements.
- * This rule can help to enable other rules that are difficult to fire across a UnionAllOperator, 
+ * This rule can help to enable other rules that are difficult to fire across a UnionAllOperator,
  * for example, eliminating common sub-expressions.
- * 
  * Example:
- * 
  * Before plan:
  * ...
  * assign [$$20, $$21] <- [funcA($$3), funcB($$6)]
- *   union ($$1, $$2, $$3) ($$4, $$5, $$6)
- *     union_branch_0
- *       ...
- *     union_branch_1
- *       ...
- *     
+ * union ($$1, $$2, $$3) ($$4, $$5, $$6)
+ * union_branch_0
+ * ...
+ * union_branch_1
+ * ...
  * After plan:
  * ...
  * union ($$1, $$2, $$3) ($$4, $$5, $$6) ($$22, $$24, $$20) ($$23, $$25, $$21)
- *   assign [$$22, $$23] <- [funcA($$1), funcB($$4)]
- *     union_branch_0
- *       ...
- *   assign [$$24, $$25] <- [funcA($$2), funcB($$5)]
- *     union_branch_1
- *       ...
+ * assign [$$22, $$23] <- [funcA($$1), funcB($$4)]
+ * union_branch_0
+ * ...
+ * assign [$$24, $$25] <- [funcA($$2), funcB($$5)]
+ * union_branch_1
+ * ...
  */
 public class PushAssignBelowUnionAllRule implements IAlgebraicRewriteRule {
 
@@ -84,6 +81,11 @@
                 continue;
             }
             AssignOperator assignOp = (AssignOperator) childOp;
+            for (Mutable<ILogicalExpression> expr : assignOp.getExpressions()) {
+                if (!expr.getValue().isFunctional()) {
+                    return false;
+                }
+            }
 
             AbstractLogicalOperator childOfChildOp = (AbstractLogicalOperator) assignOp.getInputs().get(0).getValue();
             if (childOfChildOp.getOperatorTag() != LogicalOperatorTag.UNIONALL) {