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
evenhave 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