Using Intelligent Calculation
This section provides information on turning Intelligent Calculation on and off, and using it with different types of calculations.
Turning Intelligent Calculation On and Off
By default, Intelligent Calculation is turned on.
To turn Intelligent Calculation on and off for the duration of a calculation script, use the SET UPDATECALC command in a calculation script.
Using Intelligent Calculation for a Default, Full Calculation
Intelligent Calculation provides significant performance benefits when you do a full calculation (CALC ALL) of an Essbase. If you do a full calculation, leave Intelligent Calculation turned on (the default) to take advantage of its performance benefits.
Caution:
When using Intelligent Calculation, note the information in Limitations of Intelligent Calculation.
Calculating for the First Time
When you do the first full calculation of a database, Essbase calculates every block. The performance is the same whether Intelligent Calculation is on or off.
Recalculating
When you do a full recalculation of a database with Intelligent Calculation turned on, Essbase checks each block to see whether it is marked as clean or dirty. See Intelligent Calculation and Data Block Status.
Checking data blocks has a 5% to 10% performance overhead, which is insignificant when compared to the performance gained by enabling Intelligent Calculation.
If, however, you recalculate a database in which more than approximately 80% of the values have changed, the overhead of Intelligent Calculation may outweigh the benefits. In this case, turn off Intelligent Calculation.
Using Intelligent Calculation for a Calculation Script, Partial Calculation
Essbase marks a data block as clean when it calculates the data block on a full calculation (CALC ALL) or when it calculates all dimensions in one CALC DIM command. See Marking Blocks as Clean.
In any other calculations, Essbase does not mark calculated data blocks as clean, unless you use the SET CLEARUPDATESTATUS command in a calculation script. For example, if you calculate a subset of a database or calculate a database in two calculation passes, Essbase does not mark the calculated blocks as clean, unless you use the SET CLEARUPDATESTATUS command.
The following calculation scripts do not cause Essbase to mark the calculated data blocks as clean:
FIX(“New York”)
CALC DIM(Product, Measures);
ENDFIXCALC DIM(Measures, Product);
CALC DIM(Market, Year, Scenario);Use SET CLEARUPDATESTATUS to avoid unnecessary recalculations.