Thursday, 17 January 2013

ETL THROUGH DB2

1.A typical sql of datawarehousing is actually stands for? 


 A SQL query is taking more response time to reply(more then 1hrs).
The sql is joning 6 tables. Primarily it is joining through single foreign
 key which all the tables have. But as a typical rdbms query ,there is nothing wrong with this.
But scenario is for 3 tables that column is a unique key and for other three table thata column
 is a part of unique key.So while we try to join all this 6 tables,we need to join with all
 the remaining unique key for later 3 table also. Thus query response time is quite acceptable( around 5sec).


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