WAL运送优先？

Question

In streaming replication, is there such a concept as WAL shipping priority (now or in future releases), where you could set the priority of how fast effects of a transaction should make it to standby servers?

Let's say i'm going to execute a non-critical update that would add 2GB of WAL files. It would be great if the shipping of that 2GB would not delay smaller and more important WAL files that I want to send to the standby servers immediately.

Would this be possible now or in the future?

Answer 1

In the future, this looks like a possibility.

Unknowingly you are asking for the Logical Decoding feature of PostgreSQL, that although nearly ready, may not be a solution for you today (Hint: It soon could be)... and to clarify, this is completely different from the very mature internal replication that has been available since 9.0.

You can read more about it here , but in essence, using this feature, you can define which tables to replicate, which not to. In fact you could have custom SELECT SQLs that tell the replication engine which data-set to replicate to the slaves... and if the said solution (down the line) matures enough, you could also probably prioritize data changes that get replicated off to the slaves, but I agree that its still not here yet.