Re: PostgreSQL advocacy

Bruce Momjian schrieb am 22.03.2016 um 16:07:
> For me, streaming replication fully solves the high reliability problem
> and sharding fully solves the scaling problem. Of course, if you need
> both, you have to deploy both, which gives you 100% of two solutions,
> rather than Oracle RAC which gives you 50% of each.
>
> However, I do think database upgrades are easier with Oracle RAC, and I
> think it is much easier to add/remove nodes than with sharding. For me,
> this chart summarizes it:
>
> HA Scaling Upgrade Add/Remove
> Oracle RAC 50% 50% easy easy
> Streaming Rep. 100% 25%* hard easy
> Sharding 0% 100% hard hard
>
> * Allows read scaling

To be fair: you don't need RAC in Oracle to get streaming replication.

You can use a hot-standby in Oracle the same way you do in Postgres

And if you use a "cold-standby" (where only the archive logs are applied, but the instance is not started) you don't even have to pay for the second license.

> However, I do think database upgrades are easier with Oracle RAC

I think you can do a rolling upgrade with a standby, but I'm not entirely sure.

Thomas