Hi All

I have seen some articles about this subject at one time ... can anybode
guide me ?

But when is it a very Large Dimension ? If a have a dimension table with 12
mio records but at a given
point in time there is only transactions on 10% of these dimensions - is it
then a Very Large Dimension or
isn't it a problem when there's no transactions on all the dimensions ?

\Michael V.

Michael,
Very Large Dimensions (VLD) are defined as about 4 mill members or more.
VLDs are managed in a seperate process (VLD Manager). The amount of
transactions are not an issue as this is a AS concept.

Jon Jahren

"Michael V" <123 (AT) test (DOT) com> wrote

Michael,
A seperate process (msmdvldm.exe) managing these dimensions when present in
your cubes. This process optimizes loading and processing for Very Large
Dimensions, and runs in a seperate process from the rest of you loading
dimensions. You can see VLDM as a on of the steps in the Processing window
when you manually process your shared dimensions.

If you want to, you can configure the VLD threshold in the registry. Play
with the VLDMThreshold key in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\OLAP
Server\CurrentVersion.

Jon Jahren

"Michael V" <123 (AT) test (DOT) com> wrote

Yes - found it ..

But as I understand you're messages I don't need to do anything ? Analysis
itself tackles these dimensions separately when accessing this number of
members - I can adjust the number but that would mean that Analysis then
changes the opinion of when to do VLD.

Don't I need to do anything ? Partitioning (can jo do this on dimensions
?) - mark the dimension in Analysis as VLD ?

\Michael V.

"Jon Jahren" <nospam_jon (AT) softscenario (DOT) no> wrote

Michael,
You're right - you don't have to do anything. Partitioning is not done on
dimensions so no problem here.

Jon Jahren

"Michael V" <123 (AT) test (DOT) com> wrote

4 million members definitely qualifies as being a large dimension. As Jon
indicates you can use the VLDM to manage this dimension. While VLDM does
help, it also out of process from the Analysis Service itself. This means
that there will be a performance impact associated with it. That may or may
not be of a concern for you. All you have to do take advantage of VLDM is
set the VDLMThreshold key to a value that will force the VLDM to be used.

However, I'd strongly recommend that you look at the 64-bit edition of
Analysis Services. The 64-bit edition does not use VLDM and can load this
dimension into the main server process becuase the 64-bit edition can
support much larger amounts of virtual memory.

Sean


--
Sean Boon
SQL Server BI Product Unit

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"Jon Jahren" <nospam_jon (AT) softscenario (DOT) no> wrote