Update SQLServer DDL script to use sequences instead of tables

Emulating sequences with tables causes deadlocks when running
multiple jobs at the same time. Sequences have been supported
in SQL Server since version 2012.

This commit replaces the usage of tables to emulate sequences
with real sequences. It also adds a new incrementer that is
based on sequences instead of tables.

Resolves spring-projects#1448

Author: fmbenhassine

spring-batch-core/src/main/resources/org/springframework/batch/core/schema-sqlserver.sql

@@ -76,6 +76,6 @@ CREATE TABLE BATCH_JOB_EXECUTION_CONTEXT  (
 	references BATCH_JOB_EXECUTION(JOB_EXECUTION_ID)
 ) ;
 
-CREATE TABLE BATCH_STEP_EXECUTION_SEQ (ID BIGINT IDENTITY);
-CREATE TABLE BATCH_JOB_EXECUTION_SEQ (ID BIGINT IDENTITY);
-CREATE TABLE BATCH_JOB_SEQ (ID BIGINT IDENTITY);
+CREATE SEQUENCE BATCH_STEP_EXECUTION_SEQ START WITH 0 MINVALUE 0 MAXVALUE 9223372036854775807 NO CACHE NO CYCLE;
+CREATE SEQUENCE BATCH_JOB_EXECUTION_SEQ START WITH 0 MINVALUE 0 MAXVALUE 9223372036854775807 NO CACHE NO CYCLE;
+CREATE SEQUENCE BATCH_JOB_SEQ START WITH 0 MINVALUE 0 MAXVALUE 9223372036854775807 NO CACHE NO CYCLE;

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/support/DefaultDataFieldMaxValueIncrementerFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2018 the original author or authors.
+ * Copyright 2006-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,6 +55,7 @@
  * @author Lucas Ward
  * @author Michael Minella
  * @author Drummond Dawson
+ * @author Mahmoud Ben Hassine
  * @see DatabaseType
  */
 public class DefaultDataFieldMaxValueIncrementerFactory implements DataFieldMaxValueIncrementerFactory {
@@ -113,7 +114,7 @@ else if (databaseType == SQLITE) {
 			return new SqliteMaxValueIncrementer(dataSource, incrementerName, incrementerColumnName);
 		}
 		else if (databaseType == SQLSERVER) {
-			return new SqlServerMaxValueIncrementer(dataSource, incrementerName, incrementerColumnName);
+			return new SqlServerSequenceMaxValueIncrementer(dataSource, incrementerName);
 		}
 		else if (databaseType == SYBASE) {
 			return new SybaseMaxValueIncrementer(dataSource, incrementerName, incrementerColumnName);

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/support/SqlServerSequenceMaxValueIncrementer.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.item.database.support;
+
+import javax.sql.DataSource;
+
+import org.springframework.jdbc.support.incrementer.AbstractSequenceMaxValueIncrementer;
+
+/**
+ * Incrementer for SQL Server sequences.
+ *
+ * @author Mahmoud Ben Hassine
+ * @since 5.0
+ */
+public class SqlServerSequenceMaxValueIncrementer extends AbstractSequenceMaxValueIncrementer {
+
+    public SqlServerSequenceMaxValueIncrementer(DataSource dataSource, String incrementerName) {
+        super(dataSource, incrementerName);
+    }
+
+    @Override
+    protected String getSequenceQuery() {
+        return "select next value for " + getIncrementerName();
+    }
+}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/support/DefaultDataFieldMaxValueIncrementerFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2018 the original author or authors.
+ * Copyright 2006-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,6 +35,7 @@
  * @author Lucas Ward
  * @author Will Schipp
  * @author Drummond Dawson
+ * @author Mahmoud Ben Hassine
  */
 public class DefaultDataFieldMaxValueIncrementerFactoryTests extends TestCase {
 
@@ -118,7 +119,7 @@ public void testPostgres(){
 	}
 
 	public void testMsSqlServer(){
-		assertTrue(factory.getIncrementer("sqlserver", "NAME") instanceof SqlServerMaxValueIncrementer);
+		assertTrue(factory.getIncrementer("sqlserver", "NAME") instanceof SqlServerSequenceMaxValueIncrementer);
 	}
 
 	public void testSybase(){

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/support/SqlServerSequenceMaxValueIncrementerTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.item.database.support;
+
+import javax.sql.DataSource;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Mahmoud Ben Hassine
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class SqlServerSequenceMaxValueIncrementerTests {
+
+    @Mock
+    private DataSource dataSource;
+
+    private SqlServerSequenceMaxValueIncrementer incrementer;
+
+    @Test
+    public void testGetSequenceQuery() {
+        // given
+        this.incrementer = new SqlServerSequenceMaxValueIncrementer(this.dataSource, "BATCH_JOB_SEQ");
+
+        // when
+        String sequenceQuery = this.incrementer.getSequenceQuery();
+
+        // then
+        Assert.assertEquals("select next value for BATCH_JOB_SEQ", sequenceQuery);
+    }
+}