About

Martin Klier

usn-it.de

Oracle IMPDP, ORA-1555 and UNDO_RETENTION

Many topics are to be found on the web about IMPDP and UNDO_RETENTION. This one will become a more theoretical one, around the central question: Why, please why does a huge IMPDP fail with ORA-1555 if there is too less UNDO_RETENTION configured? Like so often, these questions come from a problem. I had to impdp […]

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Oracle Grid Infrastructure 11gR2: How to clean up to repeat root.sh

To clean up a tilted installation of Oracle Grid Infrastructure isn’t that intuitive. I had to do it today, and this is my collection what to do and what to read. It’s made for repeating root.sh, that’s not allowed to run twice or more times without cleaning up in between. So first have a look […]

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Oracle: How to create a good execution plan

Sometimes you simple need to know whether a statement is fast or not, or why it is slow. (Sadly, it seems like virtually nobody wants to know why a statement is fast, but that’s another story…) Do not use EXPLAIN PLAN in such cases, it does not (can not) deal bind variables right. I’ve got  […]

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Oracle 11g Adaptive Cursor Sharing does not work with PL/SQL?

Recently, there was trouble in the air. I migrated a database into 11g to enjoy adaptive cursor sharing, but it did not adapt cursors. In the trouble shooting process, I discovered the following: Bug 8357294: ADAPTIVE CURSOR SHARING DOESN’T WORK FOR SQL FROM PL/SQL Nice one. A short quotation from the bug text: PL/SQL has […]

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Talk about Database Technology Basics at Berufsschule Wiesau

Once again, I will talk about an IT topic at Vocational School (Berufsschule) Wiesau. This year, it’s Basics of Database Technology (Grundlagen der Datenbanktechnik) for 11th and 12th-graders, who will become certified IT specialists for software development soon. Their certification is called “Fachinformatiker der Fachrichtung Anwendungsentwicklung” in German. The paper for the talk is available […]

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Oracle Technology Day Storage Optimisation – Impressions

In January, I’ve bee rather busy, so the blog was left alone. No sense in blogging just to blog. Now some content. I attended the Oracle Technology Day – Storage Optimisation in Bonn, Germany. It was a nice event, lots of information, a bit commercials, excellent catering. But this is a technical blog, let’s talk […]

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Oracle 11g: Password expired, account locked – unwanted!

Hi, it’s old news, but oracle 11g expires passwords after 180 days, and locks you out if you mistype your password 10 times, and most DBAs don’t like that. It’s unsecure, but for client-server-applications a locked account is no single-user-annoyance, it’s a downtime killing SLAs, nerves and – hopefully not – DBA jobs. So just […]

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DOAG Konferenz 2009: Impressions Day 3 (final)

Thursday 19th was the last day of DOAG Confernce 2009. Compared with the second day, the program was much more dense: For my (DBA) profile there have been several hours, where more that one talk would have been appropriate. This list is, what I collected during the day. […]

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DOAG Konferenz 2009: Impressions Day 2

As promised, today my impressions of yesterday (confusing, I know). Clarification: This is about Wednesday, November 18th. I’m still at DOAG Conference 2009 in Nuremberg. Wednesday was a silent day for my interests, especially at noon there have been less talks being of interest, but maybe they have done something for my general knowledge… So […]

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