Today I participated in the Microsoft webcast “TechNet Webcast: Data Warehousing Enhancements in Microsoft SQL Server 2008” (Event Code: 1032344497) by Torsten Grabs. Some information in this webcast was about upcoming changes in SSAS 2008.
In SSAS 2008 we should expect MDX query performance improvement as now Analysis Services will be able to deal better with cube sparsity. Cube space is generally “sparse” – values only exists for small number of dimension intersections. SSAS 2005 evaluates expressions on complete space. With SP2 SSAS 2005 does some subspace computation, but in SSAS 2008 this is improved a lot. SSAS 2008 divides the space to separate calculated members, regular members and empty space. Then it can better evaluate cells that needs to be included in calculations.
There was interesting information presented about SSAS backups. I did not know that that for SSAS 2005 backup time grows exponentially for databases over 20GB in size. This is fixed in SSAS 2008 and backup time growth now is linear. Also in SSAS 2008 Analysis Services backup storage subsystem will be replaced and all limitations on backup size will be removed.
Presenter also listed other upcoming SSAS improvements, but because of time shortage did not elaborate more:
- Query Tracing
- Writeback performance
- Read-only scalable database
- Resource monitoring
I understood that these changes will be included in the next CTP (CTP 4) that is expected in 2-3 weeks. Microsoft is planning to to CTP releases every 2-3 months.