Category Archives: Uncategorized

When Others Then John Doe; —

A few weeks ago, while doing PL/SQL code review, I came across this gem: Of course upon seeing that, my head exploded.  Then it started a chain reaction in our office with everyone’s head exploding in sequence, like in the movies where our hero sets off a sequence of claymore mines.  Some things cannot be …

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Why Every DBA Should Learn Slackware – Part 2

We just finished installing Slackware and booted it up.  I feel like I am playing Zork here: So where is my GUI?  What do I do now?  Well, Slackware comes with a pretty nice KDE desktop.  It just doesn’t start by default.  Probably a good thing if you are logged in as root. Anyway, I …

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Why every DBA should learn Slackware – Part 1

There is an old saying:  “”If you want to learn Debian, install Debian. If you want to learn Red Hat, install Fedora. If you want to learn Linux, install Slackware.” There is a truth to that statement.  It is one of the oldest distros, and I first saw it in about 1994 when it came …

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Securing your web browsing in Linux

Many years ago, when I installed Red Hat 7 as my primary Internet connected workstation, it was like the surfing the web in 1995.  Before Firefox, we had Mozilla 1.0 and it was a pleasure to use.  It was the first browser with a pop-up blocker and I could count on Linux’s Unix based security …

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The Importance of DBA_ROLLBACK_SEGS – Recovery

OK, I have successfully opened my database.  I am in a lot better position than I was I was a few days ago.  But what about my priceless Dilbert collection?  It is not like I could just go to dilbert.com and download them again, could I? SQL> select count(*) from dilbert; ORA-00604: error occurred at …

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The Importance of DBA_ROLLBACK_SEGS – 3 of 4

    Does anyone notice a pattern here with the post titles?   Anyway, I was loading my priceless collection of Dilbert strips into my database when it crashed and burned: Trying to restart the database, my undo tablespace is gone: SQL> startup ORACLE instance started. Total System Global Area 2499805184 bytes Fixed Size 2927480 bytes …

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The Importance of DBA_ROLLBACK_SEGS – 2 of 3

Yes, the original post title said “The Importance of DBA_ROLLBACK_SEGS -1 of 2”.  The second part was supposed to be where I clobbered my undo tablespace and had to use _CORRUPTED_ROLLBACK_SEGMENTS.  Apparently I can’t even clobber my tablespaces right.  My evil plan was simple: Shut the database down Nuke the rollback segment datafile from orbit …

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The importance of DBA_ROLLBACK_SEGS – 1 of 2

Unless you have been a DBA for more than 10 years, you might not have even heard of DBA_ROLLBACK_SEGS. Back in the days of Oracle6 and Oracle7, when there was no Interwebs and every kid had to walk to school uphill both ways in the snow, Oracle had rollback segments. Before we had undo tablespaces, …

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Captain Smith’s Log

Everyone knows the story of the Titanic.  She hit an iceberg on her maiden voyage which ruptured 5 of her 16 watertight compartments.  Like a RAID array, her hull was designed with redundancy in mind, and could afford the failure of up to 4 of the compartments.  Unfortunately the collision damaged the 5 forward compartments, …

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