Re: Accessing with JPA

I'm only using the rdbms on a limited basis, for an index that supports filtering and therefore needs joins, but most of my app still uses the datastore.  So I decided to just use plain jdbc.  Spring's JdbcTemplate and RowMapper facilities make it a lot easier than it used to be, and you can still use annotations for transaction demarcation.  

Actually my main requirement was a connection pool and you can use Commons DBCP easily for that.  Lastly, I intend to partition my data so it can scale linearly to N rdbms instances, so I've setup 2 datasources to start off for my dao to use (there is of course no JTA-type cross-datasource transactions but I don't need that).  Here's the config:

    <bean id="dsSearchIndex1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">

        <property name="driverClassName" value="com.google.appengine.api.rdbms.AppEngineDriver"/>

        <property name="url" value="jdbc:google:rdbms://xxxx.com:web-prod:searchindex-1/ctssearchidx?allowMultiQueries=true"/>

        <property name="username" value="xxxx"/>

        <property name="password" value="xxxx"/>

    </bean>

    <bean id="tmSearchIndex1" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

   <property name="dataSource" ref="dsSearchIndex1"></property>

    </bean>

    <tx:annotation-driven mode="aspectj" transaction-manager="dsSearchIndex1" />

    <bean id="dsSearchIndex2" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">

        <property name="driverClassName" value="com.google.appengine.api.rdbms.AppEngineDriver"/>

        <property name="url" value="jdbc:google:rdbms://xxxx.com:web-prod:searchindex-2/ctssearchidx"/>

        <property name="username" value="xxxx"/>

        <property name="password" value="xxxx"/>

    </bean>

    <bean id="tmSearchIndex2" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

   <property name="dataSource" ref="dsSearchIndex2"></property>

    </bean>

    <tx:annotation-driven mode="aspectj" transaction-manager="dsSearchIndex2" />

    <bean id="daoSearchIndex" class="com.xxxx.searchindex.SearchIndexDaoImpl">

        <property name="dsSearchIndex1" ref="dsSearchIndex1"/>

        <property name="dsSearchIndex2" ref="dsSearchIndex2"/>

    </bean>

    

(However the SDK only supports 1 db locally, accessing any of these datasources in your dev environment will connect you to the one mysql db you've specified in your plugin config)