diff --git a/core/api/src/main/java/org/onlab/onos/store/service/OptimisticLockException.java b/core/api/src/main/java/org/onlab/onos/store/service/OptimisticLockException.java
deleted file mode 100644
index 090eb63..0000000
--- a/core/api/src/main/java/org/onlab/onos/store/service/OptimisticLockException.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.onlab.onos.store.service;
-
-/**
- * Exception that indicates a optimistic lock failure.
- */
-@SuppressWarnings("serial")
-public class OptimisticLockException extends PreconditionFailedException {
-}
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/PreconditionFailedException.java b/core/api/src/main/java/org/onlab/onos/store/service/PreconditionFailedException.java
deleted file mode 100644
index 8a631a0..0000000
--- a/core/api/src/main/java/org/onlab/onos/store/service/PreconditionFailedException.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package org.onlab.onos.store.service;
-
-/**
- * Exception that indicates a precondition failure.
- * Scenarios that can cause this exception:
- * <ul>
- * <li>An operation that attempts to write a new value iff the current value is equal
- * to some specified value.</li>
- * <li>An operation that attempts to write a new value iff the current version
- * matches a specified value</li>
- * </ul>
- */
-@SuppressWarnings("serial")
-public class PreconditionFailedException extends DatabaseException {
-}
\ No newline at end of file
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/ReadStatus.java b/core/api/src/main/java/org/onlab/onos/store/service/ReadStatus.java
index 72ed356..8d8c6a3 100644
--- a/core/api/src/main/java/org/onlab/onos/store/service/ReadStatus.java
+++ b/core/api/src/main/java/org/onlab/onos/store/service/ReadStatus.java
@@ -1,6 +1,17 @@
 package org.onlab.onos.store.service;
 
+/**
+ * Status of completed read request.
+ */
 public enum ReadStatus {
-    OK,
+
+	/**
+	 * Read completed successfully.
+	 */
+	OK,
+
+    /**
+     * Read failed due to an invalid table name being specified.
+     */
     NO_SUCH_TABLE
 }
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/WriteAborted.java b/core/api/src/main/java/org/onlab/onos/store/service/WriteAborted.java
deleted file mode 100644
index a2ebd2a..0000000
--- a/core/api/src/main/java/org/onlab/onos/store/service/WriteAborted.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package org.onlab.onos.store.service;
-
-
-/**
- * Exception that indicates a write operation is aborted.
- * Aborted operations do not mutate database state is any form.
- */
-@SuppressWarnings("serial")
-public class WriteAborted extends DatabaseException {
-}
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/WriteStatus.java b/core/api/src/main/java/org/onlab/onos/store/service/WriteStatus.java
index 8c9990a..2267838 100644
--- a/core/api/src/main/java/org/onlab/onos/store/service/WriteStatus.java
+++ b/core/api/src/main/java/org/onlab/onos/store/service/WriteStatus.java
@@ -1,8 +1,27 @@
 package org.onlab.onos.store.service;
 
+/**
+ * Status of completed write request.
+ */
 public enum WriteStatus {
+
+	/**
+	 * Write completed successfully.
+	 */
     OK,
+
+    /**
+     * Write was aborted (ex: if one or more write operations in a batch fail, others are aborted)
+     */
     ABORTED,
+
+    /**
+     * Write failed due to pre-condition failure. (ex: version or value mis-match)
+     */
     PRECONDITION_VIOLATION,
+
+    /**
+     * Write failed due to an invalid table name being specified.
+     */
     NO_SUCH_TABLE,
 }