How Oracle uses Space, sort of.

Space. The Final Frontier.
My long-suffering Mrs does enjoy a bit of sci-fi especially if some hunky all-action type is wandering around with his shirt off.
“That man has such a nice personality”, she may well sigh, staring dreamily at the screen.

As with any software Oracle error messages can look as if they’ve been put together in some alien language.
This is especially true if your fairly new to Oracle.
When you get space errors in Oracle, the answer is not necessarily to simply add more space.

What we’re going to look at here is :

  • what a tablespace is and the various things they are used for
  • how redo logs work ( and how they are archived)
  • some of the space related errors you may encounter and what the underlying causes may be

Of necessity, I’ve made some generalisations here. The purpose of this post is not to provide an in-depth technical guide to the inner workings of Oracle. Rather it is to provide enough information for you to work out whether you should be looking up the phone number for your hard-pressed DBA, or looking at that bit of code you’ve just run.

Also, like the author, this post is a bit short of cache. For the sake of simplicity (and that weak pun), I’m going to pretend that Oracle uses memory in one amorphous lump.
Additionally, I’ve not taken into consideration Direct Path Inserts.

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ORACLE Transactions and Fishing on the Underground

It’s that time of year again. Yes, it is the season to be snotty.
“Man-flu”, was Nurse Debbie’s considered medical opinion. Admittedly, she’s feeling a bit under the weather herself and, as we all know, “Bird-flu” is a far more serious condition.

I think I must have picked up this particular bug during my daily commute, which currently involves quite a lot of time on the Tube.

In order to pass the time in the morning crush that is the Northern Line, I’ve taken on a challenge from Simon.

He claims that, apart from St. John’s Wood, there is no other tube station that does not contain at least one letter from the word “Mackrel”.

Whilst this may seem a somewhat esoteric fact, it’s probably quite appropriate to look for bits of fish whilst wedged into a Tube train like a sardine.

The tube map itself includes station on the Overground Network as well as the DLR so, ironically, this does provide a bit of “wiggle-room” for my Mackrel search.

All of which serves to act as an example in the following exploration of how Oracle transactions work…
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