Teradata Cookbook

How to do it...

1. Hit F6 by selecting the query to get the explain or write the EXPLAIN keyword before the query and press F5:

ExplainInsert  Into  test01.webclicks select * From    au.az_clicks;

2. First, we lock a distinct test01."pseudo table" for write on a RowHash to prevent global deadlock for test01.webclicks.
3. Next, we lock a distinct au."pseudo table" for read on a RowHash to prevent global deadlock for au.az_clicks.
4. We lock test01.webclicks for write, and we lock au.az_clicks for read.
5. We do an all-AMPs RETRIEVE step from au.az_clicks by way of an all-rows scan with no residual conditions into Spool 1 (all_AMPs), which is built locally on the AMPs. The input table will not be cached in memory, but it is eligible for synchronized scanning ...