How do you optimize outline?
Usually the outline is optimized using the hourglass design for dimension ordering i.e,
· Dimension with Accounts tag
· Dimension with Time tag
· Largest Dense dimension
· Smallest dense dimension
· Smallest Sparse dimension
· Largest Sparse dimension
What are the ways to improve performance during data loads?
There are several ways to optimize load
1. Grouping of Sparse member combinations
2. Making the data source as small as possible
3. Making source fields as small as possible
4. Positioning the data in the same order as the outline
5. Loading from Essbase Server
6. Managing parallel data load processing
What are the design considerations for calculation optimization?
You can configure a database to optimize calculation performance. The best configuration for the site depends on the nature and size of the database.
· Block Size(8Kb to 100Kb) and Block Density
· Order of Sparse Dimensions
· Incremental Data Loading
· Database Outlines with Two or More Flat Dimensions
· Formulas and Calculation Scripts
When does Fragmentation occur?
Fragmentation is likely to occur with the following:
· Read/write databases that users are constantly updating with data
· Databases that execute calculations around the clock
· Databases that frequently update and recalculate dense members
· Data loads that are poorly designed
· Databases that contain a significant number of Dynamic Calc and Store members
· Databases that use an isolation level of uncommitted access with commit block set to zero
How can you measure fragmentation?
You can measure fragmentation using the average clustering ratio or average fragmentation Quotient.
Using the average fragmentation quotient
Any quotient above the high end of the range indicates that reducing fragmentation may help performance
Small (up to 200 MB) 60% or higher
Medium (up to 2 GB) 40% or higher
Large (greater than 2 GB) 30% or higher
Using the average clustering ratio:
The average clustering ratio database statistic indicates the fragmentation level of the data (.pag) files. The maximum value, 1, indicates no fragmentation.
How do you can prevent and remove fragmentation?
You can prevent and remove fragmentation:
· To prevent fragmentation, optimize data loads by sorting load records based upon sparse dimension members. For a comprehensive discussion of optimizing data load by grouping sparse members.
· To remove fragmentation, perform an export of the database, delete all data in the database with CLEARDATA, and reload the export file.
· To remove fragmentation, force a dense restructure of the database.
Why is database restructuring?
As your business changes, you change the Essbase database outline to capture new product lines, provide information on new scenarios, reflect new time periods, etc. Some changes to a database outline affect the data storage arrangement, forcing Essbase to restructure the database.
What are the types of database restructuring?
The two ways by which a database restructure is triggered:
- Implicit Restructures
What are the conditions affecting Database restructuring?
Intelligent Calculation, name changes, and formula changes affect database restructuring:
· If you use Intelligent Calculation in the database, all restructured blocks are marked as dirty whenever data blocks are restructured. Marking the blocks as dirty forces the next default Intelligent Calculation to be a full calculation.
· If you change a name or a formula, Essbase does not mark the affected blocks as dirty. Therefore, you must use a method other than full calculation to recalculate the member or the database.
What are the files used during Restructuring?
When Essbase restructures both the data blocks and the index, it uses the files described
Essbase data fileessxxxxx.ind
Essbase index filedbname.esm
Essbase kernel file that contains control information used for db recoverydbname.tct
Transaction control tabledbname.ind
Free fragment file for data and index free fragmentsdbname.otl
Outline file in which is defined all metadata for a database and how data is storedWhat are the actions that improve performance for restructuring?
There are a number of things you can do to improve performance related to database restructuring:
· If you change a dimension frequently, make it sparse. · Use incremental restructuring to control when Essbase performs a required database restructuring. · Select options when you save a modified outline that reduce the amount of restructuring required.
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