Explain the use of lookup tables and Aggregate tables.At the time of updating the data warehouse, a lookup table is used. When placed on the fact table or warehouse based upon the primary key of the target, the update is takes place only by allowing new records or updated records depending upon the condition of lookup.
The materialized views are aggregate tables. It contains summarized data. For example, to generate sales reports on weekly or monthly or yearly basis instead of daily basis of an application, the date values are aggregated into week values, week values are aggregated into month values and month values into year values. To perform this process @aggregate function is used.
Explain the use lookup tables and Aggregate tables.An aggregate table contains summarized view of data. Lookup tables, using the primary key of the target, allow updating of records based on the lookup condition.