MS SQL Server OLAP - MSAS 2gb/3gb limit...

Author

MSAS 2gb/3gb limit...

BATMAN

2005-09-16, 8:24 pm

Is the 2gb/3gb limit physical memory or virtual memory?

Thanks

Darren Gosbell

2005-09-17, 3:24 am

The 2/3 Gb limit (depending on how your boot.ini file is configured)
affects the total addressable memory space. So that probably be what you
mean when you say virtual memory.

That is, if you have a 32bit box with more than 3Gb of physical RAM AS2K
can still only address (use) a maximum of 3Gb.

The only way to get over this limit is to use a 64bit operating system.

The other thing to note on this is that for the dimension cache, AS2k
can launch a separate process called VLDM (very-large-dimension-manager)
that can give you an addition 2Gb of memory for large dimensions at the
cost of some performance for inter-process communication.

--
Regards
Darren Gosbell [MCSD]
< dgosbell_at_yahoo_do
t_com>
Blog: http://www.geekswithblogs.net/darrengosbell

In article <E1A4F4BA-7843-46DC-98B1- A53ABDF6EA6D@microso
ft.com>,
BATMAN@discussions.microsoft.com says...
> Is the 2gb/3gb limit physical memory or virtual memory?
>
> Thanks
>

BATMAN

2005-09-19, 1:25 pm

Thanks for the response…

To be more specific… What I’m asking is if the MSAS 2/3gb limit (3gb with
the /3gb switch in the boot.ini) is related to only physical memory or total
virtual memory. Virtual being (physical + pagefile)… For example, if MSAS
consumed 1.5 physical and .5 paging file, would MSAS be at it’s max?

Thanks again!

"Darren Gosbell" wrote:

> The 2/3 Gb limit (depending on how your boot.ini file is configured)
> affects the total addressable memory space. So that probably be what you
> mean when you say virtual memory.
>
> That is, if you have a 32bit box with more than 3Gb of physical RAM AS2K
> can still only address (use) a maximum of 3Gb.
>
> The only way to get over this limit is to use a 64bit operating system.
>
> The other thing to note on this is that for the dimension cache, AS2k
> can launch a separate process called VLDM (very-large-dimension-manager)
> that can give you an addition 2Gb of memory for large dimensions at the
> cost of some performance for inter-process communication.
>
> --
> Regards
> Darren Gosbell [MCSD]
> < dgosbell_at_yahoo_do
t_com>
> Blog: http://www.geekswithblogs.net/darrengosbell
>
> In article <E1A4F4BA-7843-46DC-98B1- A53ABDF6EA6D@microso
ft.com>,
> BATMAN@discussions.microsoft.com says...
>
>

Dave Wickert [MSFT]

2005-09-19, 8:24 pm

In operating system terms is it "virtual address space". So you are right,
it is really working set plus page file usage.

In practical terms, it also relates to recommended physical memory used by
AS.
This is because Windows as an operating system doesn't really like to page.
It has the provision but you won't get peak throughput from the system if it
does a lot of paging.
--
Dave Wickert [MSFT]
dwickert@online.microsoft.com
Program Manager
BI Systems Team
SQL BI Product Unit (Analysis Services)
--
This posting is provided "AS IS" with no warranties, and confers no rights.

"BATMAN" <BATMAN@discussions.microsoft.com> wrote in message
news:22646394-2268-426B-A36E- FCD55C8EB372@microso
ft.com...[color=darkred]
> Thanks for the response.
>
> To be more specific. What I'm asking is if the MSAS 2/3gb limit (3gb with
> the /3gb switch in the boot.ini) is related to only physical memory or
> total
> virtual memory. Virtual being (physical + pagefile). For example, if
> MSAS
> consumed 1.5 physical and .5 paging file, would MSAS be at it's max?
>
> Thanks again!
>
>
> "Darren Gosbell" wrote:
>

BATMAN

2005-09-20, 1:24 pm

Dave,

Thanks for your response...

I'm sure we're saying the same thing but I just want to clarify, only
because I'm trying to ensure that what I believe to be true is really true.
I'll start off with the definitions that I know:

Private Bytes = Virtural Memory space, physical or (physical + pagefile),
reserved for the given process

Virtual Bytes = Physical Memory or (physical + pagefile)

Working Set = Recently accessed pages in Virtual memory (physical or
(physical + pagefile))

Now my question/clarification… You said that the memory an application can
address is “working set plus page file usage”. My confusion comes from that
I think of Working Set to be the above definition. So I would say that the
total memory MSAS can address, depending if /3GB or /USERVA are used, is
2-3gb Virtual Memory. Am I correct to assume that?

Again, I apologize if I’m splitting hairs… It’s just that some of our
systems require that level of tuning and I just want a reality check.

Thanks…

"Dave Wickert [MSFT]" wrote:

> In operating system terms is it "virtual address space". So you are right,
> it is really working set plus page file usage.
>
> In practical terms, it also relates to recommended physical memory used by
> AS.
> This is because Windows as an operating system doesn't really like to page.
> It has the provision but you won't get peak throughput from the system if it
> does a lot of paging.
> --
> Dave Wickert [MSFT]
> dwickert@online.microsoft.com
> Program Manager
> BI Systems Team
> SQL BI Product Unit (Analysis Services)
> --
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>
> "BATMAN" <BATMAN@discussions.microsoft.com> wrote in message
> news:22646394-2268-426B-A36E- FCD55C8EB372@microso
ft.com...
>
>
>

Dave Wickert [MSFT]

2005-09-21, 7:23 am

Correct.
--
Dave Wickert [MSFT]
dwickert@online.microsoft.com
Program Manager
BI Systems Team
SQL BI Product Unit (Analysis Services)
--
This posting is provided "AS IS" with no warranties, and confers no rights.

"BATMAN" <BATMAN@discussions.microsoft.com> wrote in message
news:3D4AAB5A-AF4A-4524-86AD- E351A9B5C111@microso
ft.com...[color=darkred]
> Dave,
>
> Thanks for your response...
>
> I'm sure we're saying the same thing but I just want to clarify, only
> because I'm trying to ensure that what I believe to be true is really
> true.
> I'll start off with the definitions that I know:
>
> Private Bytes = Virtural Memory space, physical or (physical + pagefile),
> reserved for the given process
>
> Virtual Bytes = Physical Memory or (physical + pagefile)
>
> Working Set = Recently accessed pages in Virtual memory (physical or
> (physical + pagefile))
>
> Now my question/clarification. You said that the memory an application
> can
> address is "working set plus page file usage". My confusion comes from
> that
> I think of Working Set to be the above definition. So I would say that
> the
> total memory MSAS can address, depending if /3GB or /USERVA are used, is
> 2-3gb Virtual Memory. Am I correct to assume that?
>
> Again, I apologize if I'm splitting hairs. It's just that some of our
> systems require that level of tuning and I just want a reality check.
>
> Thanks.
>
>
>
>
> "Dave Wickert [MSFT]" wrote:
>

BATMAN

2005-09-21, 8:24 pm

Thanks Dave!

"Dave Wickert [MSFT]" wrote:

> Correct.
> --
> Dave Wickert [MSFT]
> dwickert@online.microsoft.com
> Program Manager
> BI Systems Team
> SQL BI Product Unit (Analysis Services)
> --
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>
> "BATMAN" <BATMAN@discussions.microsoft.com> wrote in message
> news:3D4AAB5A-AF4A-4524-86AD- E351A9B5C111@microso
ft.com...
>
>
>

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