Search

Top 60 Oracle Blogs

Recent comments

August 2013

LAOTN Tour (Southern Leg) : UYOUG…

The trip from Lima to Montevideo took quite a long time. First I flew back to Santiago, then from there to Montevideo, Uruguay. The drive from the airport to the hotel was pretty cool. It was dark, but we were driving along the coast and the city was all lit up. We arrived quite late, so we dropped off our stuff at the hotel and went out to eat.

12c Asynchronous Global Index Maintenance Part III (Re-Make/Re-Model)

As I discussed previously in Part I, the space occupied by orphaned row entries associated with asynchronously maintained global indexes is not automatically reclaimed by subsequent DML operations within the index. Hence the need to clean out these orphaned index entries via the various options discussed in Part II. However, a good question by Jason […]

AMIS presenteert: Twee-daagse Masterclass PL/SQL 12c door Steven Feuerstein

Steven Feuerstein, dé PL/SQL autoriteit, komt op 12 en 13 december naar AMIS in Nieuwegein. Twee dagen lang verzorgt hij een masterclass waar u intensief door hem persoonlijk gecoached wordt. Intensief en persoonlijk Normaal verzorgt hij seminars waar hij vanaf een podium voor een grote groep mensen presenteert. Nu hij een AMIS masterclass geeft ontstaat

Read More...

12c Asynchronous Global Index Maintenance Part II (The Space Between)

In Part I, I discussed how global indexes can now be asynchronously maintained in Oracle 12c when a table partition is dropped or truncated. Basically, when a table partition is dropped/truncated with the UPDATE GLOBAL INDEXES clause, Oracle simply keeps track of the object numbers of those table partitions and ignores any corresponding rowids within the […]

12c subquery factoring

I’ve written a few notes about anomalies in subquery factoring (with subquery) in the past, principally making a fuss about the fact that moving an inline view into a “with subquery” can cause a plan to change even when the internal code moves the subquery back in line. With the arrival of 12c one of my first sets of tests was to rerun all the examples to see how many of them had been addressed. I hadn’t written about as many examples as I had thought, and some of them had been fixed before 12c, but here are few references to a couple of outstanding items that I thought worth a mention:

Interview

The interview I did with Timur Akhmadeev while visiting Moscow is now online. 90 minutes ! Just got through the first 6 minutes and haven’t embarrassed myself yet: http://timurakhmadeev.wordpress.com/2013/08/05/interview-with-jonathan-lewis/

12 notes

This is just a temporary note to advertise the fact that I’ve added Steve Karam’s collation of blog links on 12c features to the top of the list of links to the right of the page (12c Notes).

LAOTN Tour (Southern Leg) : Day off in Lima, Peru

I actually got a day off from travelling and presenting yesterday. I would have loved to see Macchu Picchu, but that would take more time than I had available, so instead I went to see Pachacamac, which is about 30 minutes from the city. It is a really big site, about 10 hectares. It must have looked amazing in its heyday. One part of the site is a cemetery, where they estimate there are 40,000 mummies. What with that and the whole human sacrifice thing, it was kind-of freaky. I shall have to get some more information about it and scare my nephews with the story. :)

I took quite a lot of photos, but they don’t really do the site justice.

The Fall of Hyperion

The Fall of Hyperion is the second book in the Hyperion Cantos series by Dan Simmons.

I’m not really sure what to say about The Fall of Hyperion. On the one hand, I was very interested to see what happened to the characters from the previous book. On the other hand, this book was much less focussed and quite disjointed at times. It didn’t help that it took me a long time to get through it, reading it in small snippets, rather than a few long sittings.

Despite my minor misgivings, I’ve already started the next book in the series and I’m keen to see how this plays out.

Cheers

Tim…

PS. I’ve just checked the dates between this post and the one from the proceeding book. It took about 2 months to get through it. I’m sure that has a big factor on my perception of it.

Bloom Filter

I’ve posted this note as a quick way of passing on an example prompted by a twitter conversation with Timur and Maria about Bloom filters:

The Bloom filter (capital B because it’s named after a person) is not supposed to appear in Oracle plans unless the query is executing in parallel but here’s an example which seems to use a serial Bloom filter.  Running in 11.2.0.3 and 12.1.0.1 (the results shown are the latter – the numbers are slightly different between versions):