title: Transaction across databases (schemas) on MariaDB does't work, but on Mysql works
body: <p>I had a production application where we have Mysql 5.6, with two Database (dbA, and dbB) on same instance. </p>
  
  <p>We have some processing, where data is updated on both the databases and we do transaction. So either the changes happen on both, or they dont. Things work exactly that way when using Mysql.</p>
  
  <p>We had some hierarchical tables, which is why CTEs became attractive. Since Mysql doesnt support CTE till date, we thought of moving to MariaDB 10.2. So we did that, and suddenly, transaction across database have stopped to work.</p>
  
  <p>The updates happen on dbA, but if there's issue with update in dbB, then changes on dbA dont get rolled back!</p>
  
  <p>Note that I've not changed any backend code (Using same mysqli driver for php). </p>
  
  <p>Any pearls of wisdom would massively help.</p>