diff --git a/asterix-test-framework/src/main/java/edu/uci/ics/asterix/testframework/context/TestCaseContext.java b/asterix-test-framework/src/main/java/edu/uci/ics/asterix/testframework/context/TestCaseContext.java
index cee292e..a52ede0 100644
--- a/asterix-test-framework/src/main/java/edu/uci/ics/asterix/testframework/context/TestCaseContext.java
+++ b/asterix-test-framework/src/main/java/edu/uci/ics/asterix/testframework/context/TestCaseContext.java
@@ -19,6 +19,7 @@
 import java.util.Collections;
 import java.util.List;
 
+import edu.uci.ics.asterix.testframework.xml.CategoryEnum;
 import edu.uci.ics.asterix.testframework.xml.TestCase;
 import edu.uci.ics.asterix.testframework.xml.TestCase.CompilationUnit;
 import edu.uci.ics.asterix.testframework.xml.TestGroup;
@@ -158,9 +159,11 @@
         private void addContexts(File tsRoot, TestSuite ts, List<TestGroup> tgPath, List<TestCaseContext> tccs) {
             TestGroup tg = tgPath.get(tgPath.size() - 1);
             for (TestCase tc : tg.getTestCase()) {
-                tccs.add(new TestCaseContext(tsRoot, ts, tgPath.toArray(new TestGroup[tgPath.size()]), tc));
+		if (tc.getCategory() != CategoryEnum.SLOW) {
+		    tccs.add(new TestCaseContext(tsRoot, ts, tgPath.toArray(new TestGroup[tgPath.size()]), tc));
+		}
             }
             addContexts(tsRoot, ts, tgPath, tg.getTestGroup(), tccs);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/asterix-test-framework/src/main/resources/Catalog.xsd b/asterix-test-framework/src/main/resources/Catalog.xsd
index 632d6ad..763309e 100644
--- a/asterix-test-framework/src/main/resources/Catalog.xsd
+++ b/asterix-test-framework/src/main/resources/Catalog.xsd
@@ -135,6 +135,7 @@
 
                <!-- This name is always equal to the name of the test case -->
                <xs:attribute name="name" type="xs:string" use="required"/>
+
             </xs:complexType>
          </xs:element>
 
@@ -150,8 +151,24 @@
 
       <xs:attribute name="FilePath" type="test:SimplifiedRelativeFilePath" use="required"/>
       <xs:attribute name="date" type="xs:date" use="required"/>
+      <xs:attribute name="category" type="test:category-enum"/>
    </xs:complexType>
 
+   <!-- category-enum type                                                   -->
+   <!--    Identify which category of test this is. Currently only "slow".   -->
+
+   <xs:simpleType name="category-enum">
+      <xs:annotation>
+         <xs:documentation>
+            Identify the category of test, for limiting when it is run.
+         </xs:documentation>
+      </xs:annotation>
+
+      <xs:restriction base="xs:string">
+         <xs:enumeration value="slow"/>
+      </xs:restriction>
+   </xs:simpleType>
+
    <!-- comparison-enum type                                                 -->
    <!--    Identify the type of comparison used to determine whether an      -->
    <!--    expected result and an actual result match.                       -->