Tuesday, 15 February 2011

sql - Cross Database Unions -


My warehouse datamart data is divided into 3 databases on the same server. This proof has three conclusions with the concept project that were loaded in the personal database.

While dragging into a cube, I am essentially doing this: 

  SELECT * FROM DB1.dbo.Fact_Pres select Union * DB2.dbo.Fact_Pres union Selection * from DB3.dbo.Fact_Pres

Should I really strengthen the data in a table? Will this make my processing faster?

I have no problem with disk space - I want to apply the best solution.

In either case, can you help me understand why, why do you suggest that it will be optimal? Cross-Database Query (to a lesser extent) is slower than the database, if you click

If there are three separate tables, then it is advisable to use different schemas within the same DB. If this is a fact table, then it is best to load and use split in a single fact table if the size is very large.

When it comes to ETL, this suggestion should be loaded into a separate schema in the ETL staging table - such as ETL - within the same DB and the fact sheet from there.

Recommendations are from .

Also keep in mind that the foreign key can not be used in the database.


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