diff --git a/src/main/java/org/usf/jquery/core/DBColumn.java b/src/main/java/org/usf/jquery/core/DBColumn.java
index 437d7df..087850e 100644
--- a/src/main/java/org/usf/jquery/core/DBColumn.java
+++ b/src/main/java/org/usf/jquery/core/DBColumn.java
@@ -452,7 +452,7 @@ public JDBCType getType() {
 
 			@Override
 			public boolean resolve(QueryBuilder builder) {
-				return true; //agg
+				return false; //agg
 			}
 			
 			@Override
diff --git a/src/main/java/org/usf/jquery/core/OperationColumn.java b/src/main/java/org/usf/jquery/core/OperationColumn.java
index 6888893..8e67c43 100644
--- a/src/main/java/org/usf/jquery/core/OperationColumn.java
+++ b/src/main/java/org/usf/jquery/core/OperationColumn.java
@@ -61,8 +61,7 @@ else if(operator.is("OVER")) {
 			}
 			return requirePartition().resolve(builder); //no aggregation
 		}
-		return operator.is(ConstantOperator.class) 
-				|| tryResolveAll(builder, args);
+		return !operator.is(ConstantOperator.class) && tryResolveAll(builder, args);
 	}
 	
 	@Override
diff --git a/src/main/java/org/usf/jquery/core/Operator.java b/src/main/java/org/usf/jquery/core/Operator.java
index e3f5fdb..659ae78 100644
--- a/src/main/java/org/usf/jquery/core/Operator.java
+++ b/src/main/java/org/usf/jquery/core/Operator.java
@@ -166,6 +166,10 @@ static TypedOperator rpad() {
 		return new TypedOperator(VARCHAR, function("RPAD"), required(BIGINT, VARCHAR), required(INTEGER), required(VARCHAR));
 	}
 
+	static TypedOperator age() { //td interval type
+		return new TypedOperator(VARCHAR, function("AGE"), required(DATE, TIMESTAMP, TIMESTAMP_WITH_TIMEZONE), optional(DATE, TIMESTAMP, TIMESTAMP_WITH_TIMEZONE));
+	}
+
 	//temporal functions
 	
 	static TypedOperator year() {
@@ -252,6 +256,10 @@ static TypedOperator varchar() {
 		return new TypedOperator(VARCHAR, cast("VARCHAR"), required(), optional(INTEGER)); //any
 	}
 	
+	static TypedOperator timestamp() {
+		return new TypedOperator(TIMESTAMP, cast("TIMESTAMP"), required(VARCHAR, DATE)); 
+	}
+	
 	static TypedOperator date() {
 		return new TypedOperator(DATE, cast("DATE"), required(VARCHAR, TIMESTAMP, TIMESTAMP_WITH_TIMEZONE)); 
 	}
@@ -260,10 +268,6 @@ static TypedOperator time() {
 		return new TypedOperator(TIME, cast("TIME"), required(TIMESTAMP, TIMESTAMP_WITH_TIMEZONE));
 	}
 	
-	static TypedOperator timestamp() {
-		return new TypedOperator(TIMESTAMP, cast("TIMESTAMP"), required(VARCHAR, DATE)); 
-	}
-	
 	static TypedOperator integer() {
 		return new TypedOperator(INTEGER, cast("INTEGER"), required(VARCHAR, DOUBLE));
 	}