postgresql - How to detect a Prepared Transaction inside a trigger

Question

I have a problem with existing database code (a trigger) that call a function trigger that use the NOTIFY command, which is not supported in the context of a prepared transaction.

My question is simple : from the function trigger, is there a way to detect that we are in the context of a prepared transaction ?

Thanks in advance.

Answer 1

使用prepared transactions和两阶段提交没有办法检测到当前事务会被提交，因为你还没有PREPAREd事务；在触发器运行之前，事务不知道它会经历两阶段提交。PostgreSQL 不需要你BEGIN TRANSACTION FOR TWO PHASE COMMIT（想象的语法）或类似的东西。

您可以测试max_prepared_transactions> 0 inpg_settings以查看是否启用了准备好的事务，但是在它发生之前无法知道是否会使用 2PC。