rewrite post processor; refactoring; tests
diff --git a/src/main/resources/default-config.xml b/src/main/resources/default-config.xml
index 7d21bdd..db14aab 100644
--- a/src/main/resources/default-config.xml
+++ b/src/main/resources/default-config.xml
@@ -60,20 +60,21 @@
         <property name="properties" ref="props"/>
     </bean>
 
+    <!--class="org.apache.commons.dbcp2.BasicDataSource"-->
     <bean id="dataSource"
-          class="org.apache.commons.dbcp2.BasicDataSource"
+          class="org.springframework.jdbc.datasource.SingleConnectionDataSource"
           lazy-init="true">
         <property name="driverClassName" value="${jdbc.driverClassName}"/>
         <property name="url" value="${jdbc.url}"/>
         <property name="username" value="${jdbc.username}"/>
         <property name="password" value="${jdbc.password}"/>
         <!-- relevant for single connection datasource and sqlite -->
-        <!--<property name="suppressClose">-->
-        <!--<value>true</value>-->
-        <!--</property>-->
-        <property name="initialSize" value="1"/>
-        <property name="maxIdle" value="1"/>
-        <property name="poolPreparedStatements" value="true"/>
+        <property name="suppressClose">
+            <value>true</value>
+        </property>
+        <!--<property name="initialSize" value="1"/>-->
+        <!--<property name="maxIdle" value="1"/>-->
+        <!--<property name="poolPreparedStatements" value="true"/>-->
     </bean>
 
     <!-- to configure database for sqlite, mysql, etc. migrations -->