delete mapping - performance problem
456324Oct 5 2005 — edited Jan 16 2007I am very new to both Oracle and Warehouse Builder and have run into a problem of a delete mapping taking an extremely long time to run.
I have two tables, and need to delete data from one table if data with a match on two columns exists in the other table. When I run this delete as a straight SQL query, it takes a fraction of a second. My mapping, however, runs for about 2-1/2 hours. Here's how the mapping is set up:
Source table:
Loading type: none
Match by constraint: No constraints
Target table:
Loading type: delete
Match by constraint: No constraints
For both attributes that are matched: all loading properties are set to NO except for "Match column when deleting row" which is set to YES
Both tables contain around 50,000 rows, of which about 500 need to be deleted from the target table. The mapping execution produced correct results, but the performance is unacceptable. Would greatly appreciate any suggestions on how to reduce the execution time!
Thanks, Rachel