diff --git a/spring-batch-core/src/main/resources/schema-db2.sql b/spring-batch-core/src/main/resources/schema-db2.sql
index b14042528..947fd9954 100644
--- a/spring-batch-core/src/main/resources/schema-db2.sql
+++ b/spring-batch-core/src/main/resources/schema-db2.sql
@@ -21,8 +21,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID BIGINT  PRIMARY KEY ,
 	VERSION BIGINT,  
 	JOB_INSTANCE_ID BIGINT NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -36,7 +36,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL BIGINT ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -49,7 +49,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID BIGINT NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT BIGINT , 
 	ITEM_COUNT BIGINT , 
diff --git a/spring-batch-core/src/main/resources/schema-derby.sql b/spring-batch-core/src/main/resources/schema-derby.sql
index 1e4e148ed..dc5df63d9 100644
--- a/spring-batch-core/src/main/resources/schema-derby.sql
+++ b/spring-batch-core/src/main/resources/schema-derby.sql
@@ -21,8 +21,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID BIGINT  PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
 	VERSION BIGINT,  
 	JOB_INSTANCE_ID BIGINT NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -36,7 +36,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL BIGINT ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -49,7 +49,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID BIGINT NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT BIGINT , 
 	ITEM_COUNT BIGINT , 
diff --git a/spring-batch-core/src/main/resources/schema-hsqldb.sql b/spring-batch-core/src/main/resources/schema-hsqldb.sql
index 02065ded1..30c6dfa9d 100644
--- a/spring-batch-core/src/main/resources/schema-hsqldb.sql
+++ b/spring-batch-core/src/main/resources/schema-hsqldb.sql
@@ -21,8 +21,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID BIGINT IDENTITY PRIMARY KEY ,
 	VERSION BIGINT,  
 	JOB_INSTANCE_ID BIGINT NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -36,7 +36,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL BIGINT ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -49,7 +49,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID BIGINT NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT BIGINT , 
 	ITEM_COUNT BIGINT , 
diff --git a/spring-batch-core/src/main/resources/schema-mysql.sql b/spring-batch-core/src/main/resources/schema-mysql.sql
index 20b73f58c..2297cde98 100644
--- a/spring-batch-core/src/main/resources/schema-mysql.sql
+++ b/spring-batch-core/src/main/resources/schema-mysql.sql
@@ -11,18 +11,18 @@ DROP TABLE IF EXISTS BATCH_JOB_SEQ ;
 
 -- Autogenerated: do not edit this file
 CREATE TABLE BATCH_JOB_INSTANCE  (
-	JOB_INSTANCE_ID BIGINT unsigned PRIMARY KEY ,  
+	JOB_INSTANCE_ID BIGINT  PRIMARY KEY ,  
 	VERSION BIGINT,  
 	JOB_NAME VARCHAR(100) NOT NULL , 
 	JOB_KEY VARCHAR(2500)
 );
 
 CREATE TABLE BATCH_JOB_EXECUTION  (
-	JOB_EXECUTION_ID BIGINT unsigned PRIMARY KEY ,
+	JOB_EXECUTION_ID BIGINT  PRIMARY KEY ,
 	VERSION BIGINT,  
 	JOB_INSTANCE_ID BIGINT NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -36,7 +36,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL BIGINT ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -44,12 +44,12 @@ CREATE TABLE BATCH_JOB_PARAMS  (
 );
 	
 CREATE TABLE BATCH_STEP_EXECUTION  (
-	STEP_EXECUTION_ID BIGINT unsigned PRIMARY KEY ,
+	STEP_EXECUTION_ID BIGINT  PRIMARY KEY ,
 	VERSION BIGINT NOT NULL,  
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID BIGINT NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT BIGINT , 
 	ITEM_COUNT BIGINT , 
diff --git a/spring-batch-core/src/main/resources/schema-oracle10g.sql b/spring-batch-core/src/main/resources/schema-oracle10g.sql
index 961ed245b..34d639448 100644
--- a/spring-batch-core/src/main/resources/schema-oracle10g.sql
+++ b/spring-batch-core/src/main/resources/schema-oracle10g.sql
@@ -21,8 +21,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID NUMBER(38)  PRIMARY KEY ,
 	VERSION NUMBER(38),  
 	JOB_INSTANCE_ID NUMBER(38) NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -36,7 +36,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL NUMBER(38) ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -49,7 +49,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID NUMBER(38) NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT NUMBER(38) , 
 	ITEM_COUNT NUMBER(38) , 
diff --git a/spring-batch-core/src/main/resources/schema-postgresql.sql b/spring-batch-core/src/main/resources/schema-postgresql.sql
index cc30c2817..180ffbca0 100644
--- a/spring-batch-core/src/main/resources/schema-postgresql.sql
+++ b/spring-batch-core/src/main/resources/schema-postgresql.sql
@@ -21,8 +21,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID BIGINT  PRIMARY KEY ,
 	VERSION BIGINT,  
 	JOB_INSTANCE_ID BIGINT NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -36,7 +36,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL BIGINT ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -49,7 +49,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID BIGINT NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT BIGINT , 
 	ITEM_COUNT BIGINT , 
diff --git a/spring-batch-core/src/main/sql/init.sql.vpp b/spring-batch-core/src/main/sql/init.sql.vpp
index 42e17ffff..864a88d92 100644
--- a/spring-batch-core/src/main/sql/init.sql.vpp
+++ b/spring-batch-core/src/main/sql/init.sql.vpp
@@ -10,8 +10,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID ${BIGINT} $!{IDENTITY} PRIMARY KEY $!{GENERATED},
 	VERSION ${BIGINT},  
 	JOB_INSTANCE_ID ${BIGINT} NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -25,7 +25,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL ${BIGINT} ,
 	DOUBLE_VAL ${DOUBLE},
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -38,7 +38,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID ${BIGINT} NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT ${BIGINT} , 
 	ITEM_COUNT ${BIGINT} , 
diff --git a/spring-batch-core/src/main/sql/mysql.properties b/spring-batch-core/src/main/sql/mysql.properties
index 435f465f2..fb4e98ffa 100644
--- a/spring-batch-core/src/main/sql/mysql.properties
+++ b/spring-batch-core/src/main/sql/mysql.properties
@@ -1,7 +1,7 @@
 platform=oracle10g
 # SQL language oddities
 BIGINT = BIGINT
-IDENTITY = unsigned
+IDENTITY = 
 GENERATED = 
 IFEXISTSBEFORE = IF EXISTS
 DOUBLE = DOUBLE PRECISION
diff --git a/spring-batch-core/src/test/resources/org/springframework/batch/execution/repository/dao/init.sql b/spring-batch-core/src/test/resources/org/springframework/batch/execution/repository/dao/init.sql
index a05759ae8..9ae4d01a9 100644
--- a/spring-batch-core/src/test/resources/org/springframework/batch/execution/repository/dao/init.sql
+++ b/spring-batch-core/src/test/resources/org/springframework/batch/execution/repository/dao/init.sql
@@ -10,8 +10,8 @@ CREATE TABLE BATCH_JOB_EXECUTION  (
 	JOB_EXECUTION_ID BIGINT IDENTITY PRIMARY KEY ,
 	VERSION BIGINT,  
 	JOB_INSTANCE_ID BIGINT NOT NULL,
-	START_TIME TIMESTAMP, 
-	END_TIME TIMESTAMP ,
+	START_TIME TIMESTAMP NULL, 
+	END_TIME TIMESTAMP NULL,
 	STATUS VARCHAR(10),
 	CONTINUABLE CHAR(1),
 	EXIT_CODE VARCHAR(20),
@@ -25,7 +25,7 @@ CREATE TABLE BATCH_JOB_PARAMS  (
     TYPE_CD VARCHAR(6) NOT NULL ,
 	KEY_NAME VARCHAR(100) NOT NULL , 
 	STRING_VAL VARCHAR(250) , 
-	DATE_VAL TIMESTAMP ,
+	DATE_VAL TIMESTAMP NULL,
 	LONG_VAL BIGINT ,
 	DOUBLE_VAL DOUBLE PRECISION,
 	constraint JOB_INSTANCE_PARAMS_FK foreign key (JOB_INSTANCE_ID)
@@ -38,7 +38,7 @@ CREATE TABLE BATCH_STEP_EXECUTION  (
 	STEP_NAME VARCHAR(100) NOT NULL,
 	JOB_EXECUTION_ID BIGINT NOT NULL,
 	START_TIME TIMESTAMP NOT NULL , 
-	END_TIME TIMESTAMP ,  
+	END_TIME TIMESTAMP NULL,  
 	STATUS VARCHAR(10),
 	COMMIT_COUNT BIGINT , 
 	ITEM_COUNT BIGINT ,