Percentage of total: Performance Improvement in Analysis Services 2005

Hi,

I am new to Analysis Services and was wondering if some one could
assist me with the issues I am having.

Basically we have one single table on which I need to build a cube so
that managemet can view the data in excel and have good perofrmance. I
started with AS 2000 but ran into the issue of having more than 64,000
members for a dimension level which were not unique.I tried various
suggestions given on the forum but none worked.

So I installed AS 2005 and migrated the database from AS 2000 and build the cube. However I am running into major performance issues, What I have are 2 dimensions with hierarchies Products and Time . The lowest dimesion in Products in something called Instrument Id and it is the 4th level in my hierarchy, the Time dimension has 3 levels, month being the lowest.

I read the articles which described the difference between hierarchies and attribute relationships in AS 2000 and AS 2005. So I defined atributes in my cube design for the above mentioned dimensions. However for the lowest level of detail ( Instument Id across Months ) the query takes for ever. I have the aggregation set at 70%

I know there is an issue with my design but with my limited knowledge of Analysis Serivces I am unble to focus in the right direction. Can someone help me with this

Thanks

For the clues on how to deal with performance problems and the for the better desing ideas take a look at the showcase study; project REAL

http://www.microsoft.com/technet/prodtechnol/sql/2005/projreal.mspx

Particularly in your case I can think of some reasons for slower performance.

For one, the query you are trying to run is going to scan your entire fact and is probably going to bring very big result. Try and make sure you provide a slice for your query. Select only few Instrument Id's not entire level.

Second, try and partition your measure group. Having several partitions would help to speed up your query. This is because Analysis Server can detect which partitions hold the data for the particular Instument Id's you query for and will only scan these partitions.

Edward.
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This posting is provided "AS IS" with no warranties, and confers no rights.

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Edward,

Thanks for the input, just a couple of quick follow up questions

1. When you say "make sure you provide a slice for your query. Select only few Instrument Id's not entire level" I am not sure how i would go about doing it.

2. As far a partitions I was trying to create partitions for each month of data using the query binding feature. I am not supposed to create a poartition against a dimension. and how would I go about creating partitions across a measure group.

Thanks

|||Dear All,

I'm having a problem with performance in SSAS 2005. This is the server specification:
OLAP

Server and ORACLE Data Warehouse Server (64 bit) : IBM xSeries 460,

windows 2003 EE x64 SP1, SQL Server Analysis Services 2005 x64 SP1 +

Hotfix, , ORACLE 10g R2, 8x Xeon 3 GHz, memory 8 GB. Data Warehouse is

located on drive D 400GB and OLAP is in drive E 300GB and both of them

are HDD External using SAN (Storage Area Network) RAID 5.
Application Server (32 bit) : 52 IBM xSeries 366 Windows 2003 R2 SP1 BI Serv Dev ,sqlserv 2005 8x Xeon 3GH, mem 8 GB

For

the Data warehouse I'm using ORACLE 10g R2 64 bit and for the OLAP I'm

using SSAS 2005 64 bit. I'm already installed the oracle client. For

the front-end, I'm using Proclarity.

I have problems with the

performance when querying the OLAP by using ProClarity or SSMS

(Management Studio). The response time is very low, but the CPU

Utilization is below 10% and Memory Usage not more than 50%. When I

check in the performance monitor, the I/O access is very high

continuously 100% utilization when I are running query from ProClarity

Analytics Server. For improving the performance I have applied design

aggregation for each cube. However, design aggregation cannot be made

on several cubes that have a lot of data, and have a lot of measures

and dimension (the number of fields in the table more or less 150

fields). They return 0% optimization level when I run design

aggregation.

FYI, I have done several ways for optimizing the performance such as:
1. Using MOLAP storage mode with 100% design aggregation, except several cubes that can not be made.
2. Cube design follows the best practice, e.g. using key member.
3. Separation of physical storage for data warehouse and OLAP files in different disk.
4. I also used usage-based optimization but it not works.

key points are how to improve the performance and fix the aggregation

problem that cannot be made on several cubes. I am looking forward to

hear from you soon.

Thanks in advance.|||Dear All,