#222222;">#808080;">This article liberally uses sections from #0000ff;">#0000ff;">The Threat That Lies Within by Yaniv Yehuda
Databases receive much attention so they will not become THE risk factor of IT. Budgeting DRPs, backups, top of the line DBAs – and yet, they still pose a major threat. Why?
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 […]
IDC study found that Delphix
By Tim Gorman
John Beresniewicz and I worked hand in hand on developing the performance pages in Oracle Enterprise Manager. John is one of the foremost experts on active session history (ASH) queries and he has recently posted some of his presentations on ASH to slideshare:
The Arizona Oracle User Group (AZORA) was reincarnated Tuesday July 29 by a group of six Oracle specialists interested in focusing the Oracle User Community in Arizona. A board was elected and began review of the organization bylaws (dated 1990) to be completed and presented at AZORA’s inaugural Educational Workshop tentatively scheduled for October. The new board includes: President, John King (King Training Resources); Vice-President Danny Carrizosa (OneNeck IT Solutions), Treasurer, Raj Chotalla (Intel), Secretary, Carlos Aquilar (GoNet USA), and Past-President Stephen Andert (IBM). Two of AZORA’s past presidents Steve Lemme (Oracle) and Stephen Andert (IBM) are actively involved and lending their experiences and expertise. Visit the “AZORA – Arizona Oracle User Group” LinkedIn page to learn more.
I wanted to expand on a thread in a LinkedIn group I’m part of, where one of the members wrote “It’s funny when 2 experts are arguing about who is better”, using Tom Kyte and Jonathan Lewis as examples of people they say are “Experts”.
Disclaimer: I have not spoken to Jonathan or Tom in regard to their viewpoints on this subject, so this shouldn’t be taken as them saying any of this, just my interpretation.
My perspective on that is I think you will rarely find two people who deserve the title of “Expert” will argue about “who is better”. They would discuss the technical merits of a point instead. In fact, most people I know that are generally accepted as “experts” really don’t believe they are, and most of them REALLY don’t like the term “Guru”.
Anyone who has used Oracle for a while will be familiar with the Parent/Child locking "issue" when it comes to tables and indexes on foreign keys. For many years you’d hear people crying "bug" etc but thankfully most now know the reason, and accept it as sensible behaviour.
But lets take a look at a slight variation on that theme.
Lets start with a table called "LOC" which will be our parent table in this example. Note that it is an IOT, and we’ll also have a child table "LOC_CHILD", which is also an IOT.