dual core processor / single core processor

Pietro_La_Torre

Hi,
I have a question regarding Vertica suggested Hardware.

"8 GB RAM / cpu" what does exactly mean?

If I have a dual core machine with 8 cores, do I have to count 16 cores ? (So 16 x 8 GB RAM)
OR the calculation is 8 x 8 GB RAM ?

thanks in advance

Daniel_Leybovic

Hi!

[non official answer]
Vertica sorts data - it's CPU resources. From point of view of performance you want that Vertica will sort data in-memory, i.e. in RAM. But since  Vetica is disk  database and MPP this number probably defined by these parameters - IO::read data + MPP :: process data in parallel in-memory. Due amazing Vertica architecture and algorithms, probably main bottle neck will be the IO, so amount of RAM in Vertica limited by IO.

For example:
* If you are running an analytical function (or COPY in parallel) you will want that each partition will process in parallel, ie num of CPU on maximum - with "hyper threading" enabled.
*If you have no an optimal projection, so for each partition should be enough RAM space for process like sort, etc.

>> "8 GB RAM / cpu" what does exactly mean?
I dont know what about Vertica7 in versions below 7 a right answer will be:

bash$ echo $((8 * 'nproc --all'))

nproc - print the number of processing units available

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Regards (sKwa ;-))

Daniel_Leybovic

one more, you can query RESOURCE_ACQUISITIONS table for max memory acquired.
https://my.vertica.com/docs/6.1.x/HTML/index.htm#14166.htm

Daniel_Leybovic

one more, you can query RESOURCE_ACQUISITIONS for max memroy acquired
https://my.vertica.com/docs/6.1.x/HTML/index.htm#14166.htm

Pietro_La_Torre

Hi Daniel,
thank you for your reply!
But I still have doubt on the use of either dual core or single core processors. Is there  difference?

[Deleted User]

Hello.

Your mileage may vary.

From the HP Vertica Hardware Planning Guide"  HP requires a minimum of 4 GB of memory per physical CPU core in the server, however you should run 8 GB of memory per physical core. (Note: Some heavy analytics workloads may require up to 16 GB of memory per physical core.) The memory should be at least DDR3-1333 (preferably
DDR3-1600), and should be appropriately distributed across all memory channels in the server."

Your setup has 8 physical cores, 32GB of RAM is a good place to start.  Vertica is resilient, it will run with less RAM, it will perform with more RAM.

An HP Elitebook equipped with an i7-3720QM has one processor chip, 4 physical cores, and 8 logical/virtual cpus.  16GB of ram would be a good place to start for this machine.