Chapter 8. Optimization and performance tuning 235
INNER JOIN "GOSALESDW"."GO_REGION_DIM" "GO_REGION_DIM"
ON "GO_REGION_DIM"."COUNTRY_CODE" = "GO_BRANCH_DIM"."COUNTRY_CODE"
INNER JOIN "GOSALESDW"."MRK_PROMOTION_DIM" "MRK_PROMOTION_DIM"
ON "MRK_PROMOTION_DIM"."PROMOTION_KEY" =
"SLS_SALES_FACT"."PROMOTION_KEY"
INNER JOIN "GOSALESDW"."SLS_ORDER_METHOD_DIM"
"SLS_ORDER_METHOD_DIM"
ON "SLS_ORDER_METHOD_DIM"."ORDER_METHOD_KEY" =
"SLS_SALES_FACT"."ORDER_METHOD_KEY"
INNER JOIN "GOSALESDW"."MRK_CAMPAIGN_LOOKUP"
"MRK_CAMPAIGN_LOOKUP"
ON "MRK_PROMOTION_DIM"."CAMPAIGN_CODE" =
"MRK_CAMPAIGN_LOOKUP"."CAMPAIGN_CODE"
GROUP BY
"GO_REGION_DIM"."REGION_CODE",
"GO_BRANCH_DIM"."COUNTRY_CODE",
"GO_BRANCH_DIM"."BRANCH_KEY",
"SLS_ORDER_METHOD_DIM"."ORDER_METHOD_KEY",
"MRK_CAMPAIGN_LOOKUP"."CAMPAIGN_CODE",
"MRK_PROMOTION_DIM"."PROMOTION_KEY";
8.5.3 Maintaining database aggregates
Just as a DBA has the flexibility to choose which database aggregates to create and how to
create them, the DBA is responsible for the maintenance of these database aggregate tables.
Database aggregates are usually built during a predefined ETL processing window when the
underlying warehouse data is also updated. The DBA must consider the time and processing
order that are related to the maintenance of any database aggregates that can be derived
from one another. The DBA must also consider when the cube should be started, because
in-memory aggregates are loaded at that time and can make use of the data in the database.
8.5.4 Monitoring database aggregate table hits
Cube metrics that are available in Cognos Administration can be used to monitor the
database aggregate table hit rate, along with the hit rates of the result set cache, data cache,
and aggregate cache. Select the cube and see the
Aggregate table hit rate value.

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