无法在Spring JPA中使用多线程从多个数据库中删除数据

Question

I am currently working over database operations to delete data over different database. I want to run parallel threads in Spring JPA to delete data in different databases.I am able to it sequentially.

@Transactional(propagation = Propagation.REQUIRED, isolation = Isolation.DEFAULT, readOnly = false)

public void changeAmt() {

//routing db for thread

Query query = (Query)entityManager.createNamedQuery("update_payment_card");
    recordCount=query.executeUpdate();

}

I have observed that whenever there is call to this function spring gets the DB connection using transactionInterceptor

so every time a thread call this method the underlying db connection changes.

hence only one db get effected.

Thanks in advance

Answer 1

Even if you use a connection pool, the connection object reference might differ between successive calls, because the pool will serve you the next available cached connection.

so every time a thread call this method the underlying db connection changes.

hence only one db get effected.

You usually have one DataSource configured for one DB schema. But multiple concurrent requests may use multiple connections to this data source. If you use multiple data bases, you should have multiple Data Sources and you might use JTA to have a global transaction that spans across multiple data sources.