Category Archives: Oracle

OUGN : Summary

With the exception of a 5+ hour layover in Amsterdam, the trip home was pretty straight forward. I flew to Amsterdam with Lonneke Dikmans, Ronald Luttikhuizen and Roel Hartman. During my rather excessive layover, I played catchup with all the internet stuff I missed during the trip… I must say OUGN 2014 was a pretty cool […]


OUGN : Summary was first posted on April 6, 2014 at 9:33 am.
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OUGN : Day 2

Day 2 started really early. Having got to bed about 02:00, I was up at 05:30 and thinking about my 08:30 session. The previous evening’s conversation with Brynn was playing on my mind a little (in a good way), thinking how that conversation should/would affect my session. The session itself seemed to go well. I […]


OUGN : Day 2 was first posted on April 5, 2014 at 4:22 pm.
©2012 “The ORACLE-BASE Blog“. Use of this feed is for personal non-commercial use only. If you are not reading this article in your feed reader, then the site is guilty of copyright infringement.

OUGN : Day 1

The journey to Norway was pretty straight forward, but during the second flight, from Amsterdam to OSLO, my nose and eyes started to stream. I didn’t feel ill, but I was starting to worry I might be getting ill right before a conference. I landed in Norway, got the train to the centre of OSLO […]


OUGN : Day 1 was first posted on April 5, 2014 at 4:03 pm.
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NVL() change

One of the problems of functions is that the optimizer generally doesn’t have any idea on how a predicate based on function(col) might affect the cardinality. However,  the optimizer group are constantly refining the algorithms to cover an increasing number of special cases more accurately. This is a good thing, of course – but it does mean that […]

NVL() change

One of the problems of functions is that the optimizer generally doesn’t have any idea on how a predicate based on function(col) might affect the cardinality. However,  the optimizer group are constantly refining the algorithms to cover an increasing number of special cases more accurately. This is a good thing, of course – but it does mean that […]

Unusable unique constraint

Another annoying thing about unusable indexes I’m surprised that I can’t remember coming across this before before. I want to archive some data from a bunch of partitions. Unfortunately, I can’t follow the virtuous circle of data lifecycling and partition the table in such a way that I can archive all the data from a […]

Cache anomaly

Just a quick heads-up for anyone who likes to play around with the Keep and Recycle caches. In 11g Oracle introduced the option for serial direct path reads for tablescans on tables that was sufficiently large – which meant more than the small_table_threshold – provided the table wasn’t already sufficient well cached.  (The rules mean […]

Cache anomaly

Just a quick heads-up for anyone who likes to play around with the Keep and Recycle caches. In 11g Oracle introduced the option for serial direct path reads for tablescans on tables that was sufficiently large – which meant more than the small_table_threshold – provided the table wasn’t already sufficient well cached.  (The rules mean […]

Easy – Oops.

A question came up on OTN today asking for suggestions on how to enforce uniqueness on a pair of columns only when the second column was not null. There’s an easy and obvious solution – but I decided to clone the OP’s example and check that I’d typed my definition up before posting it; and the […]

Easy – Oops.

A question came up on OTN today asking for suggestions on how to enforce uniqueness on a pair of columns only when the second column was not null. There’s an easy and obvious solution – but I decided to clone the OP’s example and check that I’d typed my definition up before posting it; and the […]