Singapore Maths Question Solution and Very Interesting Observation (The Trickster)

OK, time to reveal the solution to the somewhat tricky Singapore maths exam question I blogged previously. Remember, there were 10 dates: May 13   May 15   May 19 June 13   June 14 July 16   July 18 August 14   August 15   August 16 Bowie only knew the month of my birthday, Ziggy only knew the day. Bowie […]

Good Singapore Maths Students Would Likely Make Good Oracle DBAs (Problems)

An interesting mathematics based question from a Singapore high school exam has been doing the internet rounds in the past few days. Considering it’s aimed at high school students, it’s a tricky one and obviously designed to filter out the better students, in a country with a very good reputation for churning out mathematically gifted […]

Oracle Database In-Memory Test Drive Workshop: Canberra 28 April 2015

I’ll be running a free Oracle Database In-Memory Test Drive Workshop locally here in Canberra on Tuesday, 28th April 2015. Just bring a laptop with at least 8G of RAM and I’ll supply a VirtualBox image with the Oracle Database 12c In-Memory environment. Together we’ll go through a number of hands-on labs that cover: Configuring the Product Easily […]

12.1.0.2 Introduction to Zone Maps Part III (Little By Little)

I’ve previously discussed the new Zone Map database feature and how they work in a similar manner to Exadata Storage indexes. Just like Storage Indexes (and conventional indexes for that manner), they work best when the data is well clustered in relation to the Zone Map or index. By having the data in the table […]

Index Advanced Compression vs. Bitmap Indexes (Candidate)

A good question from Robert Thorneycroft I thought warranted its own post. He asked: “I have a question regarding bitmapped indexes verses index compression. In your previous blog titled ‘So What Is A Good Cardinality Estimate For A Bitmap Index Column ? (Song 2)’ you came to the conclusion that ‘500,000 distinct values in a 1 […]

12.1.0.2 Introduction to Zone Maps Part II (Changes)

In Part I, I discussed how Zone Maps are new index like structures, similar to Exadata Storage Indexes, that enables the “pruning” of disk blocks during accesses of the table by storing the min and max values of selected columns for each “zone” of a table. A Zone being a range of contiguous (8M) blocks. I […]

Index Compression Part VI: 12c Index Advanced Compression Block Dumps (Tumble and Twirl)

Sometimes, a few pictures (or in this case index block dumps) is better than a whole bunch of words :) In my previous post, I introduced the new Advanced Index Compression feature, whereby Oracle automatically determines how to best compress an index. I showed a simple example of an indexed column that had sections of index entries that were […]

Index Compression Part V: 12c Advanced Index Compression (Little Wonder)

I’ve finally managed to find some free time in the evening to write a new blog piece :) This will have to be the record for the longest time between parts in a series, having written Part IV of this Index Compression series way way back in February 2008 !! Here are the links to the previous articles […]

12.1.0.2 Introduction to Zone Maps Part I (Map Of The Problematique)

Zone Maps are new index-like structures that enables the “pruning” of disk blocks during accesses of the table by storing the min and max values of selected columns for each “zone” of a table. A zone is simply a range of contiguous blocks within a table. Zone Maps are similar in concept to Exadata storage […]

12.1.0.2 Introduction to Attribute Clustering (The Division Bell)

One of the really cool new features introduced in 12.1.0.2 is Attribute Clustering. This new table based attribute allows you to very easily cluster data in close physical proximity based on the content of specific columns. As I’ve discussed many times, indexes love table data that is physically clustered in a similar manner to the index […]

12.1.0.2 Released With Cool Indexing Features (Short Memory)

Oracle Database 12.1.0.2 has finally been released and it has a number of really exciting goodies from an indexing perspective which include: Database In-Memory Option, which enables specific portions of the database to be in dual format, in both the existing row based format and additionally into an efficient memory only columnar based format. This in […]

Presenting at UKOUG Tech14 Conference (Ian Fish, U K Heir)

I’ve been lucky enough to present at various conferences, seminars and user group events over the years in some 20 odd countries. But somewhere I’ve never quite managed to present at before is the place of my birth, the UK. Well this year, I’ve decided end my drought and submitted a number of papers for the UKOUG Tech14 Conference and […]

12c Index Like Table Statistics Collection (Wearing The Inside Out)

This change introduced in 12c has caught me out on a number of occasions. If you were to create a new table: And then populate it with a conventional insert: We find there are no statistics associated with the table until we explicitly collect them: But if we were to now create an index on this […]

It was 12 years ago today…

It was exactly 12 years ago today that I first presented my Index Internals – Rebuilding The Truth presentation at a local ACT Oracle User Group event. And so my association with Oracle indexes started. It would be an interesting statistic to know how many people have subsequently read the presentation :) It would no doubt result in […]

Richard Foote’s Art Work (Art Decade)

Just a quick note to say I have a new tab on the blog called “Richard Foote’s Art” where I’ll periodically upload a new piece of my art work. As the page says, they highlight both what’s in my mind (so beware) and how I like to relax in the evenings. All pieces are for […]