Re: PX Deq Credit: send blkd

From: Christian Antognini <>
Date: Sun, 21 Sep 2008 10:27:17 +0200
Message-ID: <>

Hi Martin

> It works, but the 32 parallel processes are only query processes,
> is only ONE writing process.

It would be interesting to see the execution plan. In fact, it clearly shows whether the DDL part of the statement should be parallelized or not.

> How can I make it parallel on WRITING side of the statement?

Let's try something else... In my book (at page 506 for the people having it handy) I wrote the following:

"A CTAS statement is composed of two operations that process data: the query used to retrieve data from the source tables and the insert into the target table. Each part can be executed either serially or in parallel independently of the other. However, if parallel processing is used, it is common to parallelize both operations."

Then I show three execution plans illustrating the three cases:

- Parallelization of insert only
- Parallelization of query only
- Parallelization of both operations

To produce the execution plans used for the book I used the script px_ddl.sql which is available along with all other scripts distributed with the book under So, I suggest you to download and execute it. With that script I had no problem to reproduce the expected behavior whenever I run it. If it doesn't work, I would like to see the list of all initialization parameters that are *not* set to the default.

Chris Antognini

Troubleshooting Oracle Performance, Apress 2008

Received on Sun Sep 21 2008 - 03:27:17 CDT

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