Re: PPAS capacity measuring method

Am 29.01.2016 um 05:02 schrieb 박양상:

3 days gone by and no response... bitter! Maybe because everyone was at
FOSDEM ;-)

> *We are planning on migrating ORACLE DB running on UNIX to PPAS in
> Redhat environment in a few monthes. *

Congrats on that decision. Hope to see you on plain PG one day, obviously.

> *Before migration, we need to adopt new servers to accommodate the same
> amount of transactions done on ORACLE DB. *
>
> **
> *I already know general things like the number of connections, workload
> which are very detrimental factors for capacity measuring. *

Indeed.

> **
> *We are in real situation to show the technical evidences to my
> boss before bringing new servers to our center. *

Out of curiosity (and it might explain why responses have been sparse):
"we are plannng" to me sounds like there's already a decision to switch
to PPAS. I'd reckon someone convinced someone else to do so, and I'd
further reckon that that first someone was from EDB's (pre-)sales team.

> **
>
> *Compared to ORACLE DB, how can I assure the number of CPU cores, how
> many memories, disk space necessary? *
>
> **
>
> *benchmarking stuff or something will be very helpful. *

That _so_ depends on your workload! We probably all have seen
"mission-critical, high-load" Oracle installations that in fact would
fit in a 2-CPU VM running on a single SATA disk under some desk. And
many have seen huge Oracle installations that are simply hammered with
bad SQL...

As a starting point, I'd recommend to familiarize yourself with
https://wiki.postgresql.org/wiki/Performance_Optimization
and
https://wiki.postgresql.org/wiki/Converting_from_other_Databases_to_PostgreSQL
.

There _are_ some caveats in migrating, and you might want to ask someone
(maybe the person(s) mentioned above? ;-) for guidance and assistance.
If they had a chance to run their analysis tools against your Oracle
installation already (i.e., are roughly familiar with your environment),
they might even have sizing recommendations at hand.

If that is not an option, maybe you could invest a few % of your future
savings into professional support, to get a good start into your new
DBMS realm. On second thoughts, that'd be a good idea anyway!

> **
>
> *I am really appreciated for your support if you give me any sort of
> information. *

You're welcome!
--
Gunnar "Nick" Bluth
DBA ELSTER

Tel: +49 911/991-4665
Mobil: +49 172/8853339