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Message Posted: Tue, 05 Jul 2005 @ 16:56:41 GMT

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Dieter,

Thank you for your response.

First I answer your questions so that you may be able to provide more good advice.

1. Our system is a single node machine with V2R5.

2. I ran the SQLs a month ago. I mistakenly said in my previous email that the INSERTED table was empty. It was filled with data in fact. I ran BTEQ in a SHELL script with a RUN command. The file run in BTEQ was composed with multiple SQLs in the following pattern,

          Database DbName;
          INSERT INTO Tbl1
            SELECT col1, col2, ... FROM TblA;
          INSERT INTO Tbl1
            SELECT col1, col2, ... FROM TblB;
          INSERT INTO ...

The log file showed each statement was a transaction. There were many "Insert completed." before and after the failed INSERT.

3. We use the default settings in our system. I did check the session mode. It is BTET. In the above SQLs, implicit session mode is used, and each SQL was completed with a ";" at the end of lines. It is Teradata mode.

4. No secondary indexes were created on this table.

More questions:

1. How to terminate a transaction in Teradata Manager? The utility programs are not user friendly, and they respond very slowly. They are great grandpas in computer world. You said "Starting with V2R5.1 a dba can cancel a rollback manually without help from NCR using rcvmanager". Is rcvmanager easy to use? I have not tried, and do not know how. I used other programs a little bit, and did like them at all. I like Teradata manager. After the rollback is terminated, the table has to be restored from archive.

2. If it itself is a transaction, why does ANSI or Teradata session mode matter? I think what you asked was if there were more queries in the same transaction. Otherwise, I want to know how to pick ANSI or Teradata session mode because they make differences. Is it just a portability issue.

3. Why are INSERT and DELETE so different that DELETE take 22 more times of time than INSERT? Is there something wrong or not efficient? You said V2R6 has changes? How fast will it be if we upgrade our system to V2R6? Although I do not mean I want to compare Teradata to Oracle, I can recall rollback would not take such long time in Informix. Of course, I have to mention here that the largest tables I had were about 2 million records. The INSERT time should be close to rollback time. Is it the true Teradata behavior that DELETE take much more time than INSERT? The INSERT statement did not have any joins or conditions in its SELECT statement. It should do a table scan. Optimizer should not be a factor here.

4. The purpose of my previous email about rollback issue was I wanted to know the behaviors of Teradata, and then how to deal with it. I said I might do things in a wrong way Teradata does not like or feel happy. Now my question is how to move data from one table to another? What is the way Teradata can handle better? There may be several ways, what are pros and cons?

Thanks,

Charles

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