View Filter X Report limit
01-20-2011 01:08 PM
report limit is a pre-fecth technique applied on db level , while view filter is applied on the result set afterwards by mstr analytical engine.
In other words: if you get more than governing limited rows ( standard 65000 ) from your db you are forced to use some prefetch filter like report filter or report limit, if not you may use view filter. (From MSTR Guru)
01-21-2011 02:44 AM
Basically the major difference between View filter and Report limit is the way they are caluclated and the stage at which they are calculated.
1. View filters are calculated at Post data fetching stage i.e. after fetching the data from dwh. But the report limit is applied at pre data fetching stage i.e. report limit is applied before data is fetched from dwh.
2. View filter is not applied in report sql. But the report limit is part of report query, so only qualified data is fetched from dwh.
3. The view filter is processed in Analytical engine, whereas report limit is calculated at dwh side.
4. from Performcance perspective, report limit is better than view filter as it fetches only qualified data from dwh.
I hope this will give you basic overview.
01-21-2011 03:39 AM
For difference between Report limit and Report Filter, Please refer the below TN:
TN 20060 - What is the difference between a report filter and a report limit in MicroStrategy SQL Generation Engine.
I hope this will clear your understanding.
01-22-2011 09:40 AM
Though both report filter and report limit are calculated by SQL engine (and hence they appear in sql view), when fetcing data from datawarehouse , report filter is applied before fetching the data from data warehouse and report limit - after fetching the data from the warehouse.
- Report limit is used to apply restrictions on metric calculations. Thus, only after all the metrics are calculated , report limit can be applied.
As metrics are the results of aggregations on facts , hence having clause is used to restrict the result.
- However, Report filters define the criteria to select the data that will be used to calculate the metrics. Hence, where clause comes into picture.
Hope this helps...
01-24-2011 08:53 AM
your post helped me understand it clearly.
To say it simply:
report limit is a filter on the metrics qualification at report level.
Report filer is a filter on attributes.
01-24-2011 09:37 PM
-report limits are applied at the level of the report after the metrics are caluculated but report filter is used to select the data for caluculating the metrics in the report and it also restricts the attribute elements included in the report.
-report limit specifies a set of criteria used to restrict the data returned in the rport data set after the report metrics are caluculated.
01-25-2011 05:34 AM
Report limit Filter: comes under HAVING clause in the sql. It filter only on the metric qualifaction at report level.
View Filter: https://resource.microstrategy.com/support/MainSearch.aspx?tnkey=20060&formatted=1