I am loading data from one table to another the structure of both the
tables are the same.

When I copy from the staging table to the main table I want the
staging table records to overwrite the records with the same key in
the main table.

So for example the following are the keys in both tables:

Key columns
===========
Month
Material
Year
Customer
Store

Non-Key Columns
===============
SalesQty
Sales$

If the staging table as a record with the same key columns values as
the main table I want to overwrite the non-key column values in the
main table with the values from the staging table.

Can any of you kindly share how this can be done most efficiently as I
would have more than 2 million records in the staging table and about
3 mill records in the main table at any point of time.

Thanks
Karen

Karen

Use UPDATE StTable SET col1=MainTable.col1
FROM MainTable JOIN StTable ON MainTable.PK=StTable.PK






"Karen Middleton" <karenmiddleol (AT) yahoo (DOT) com> wrote