The Hitchhiker’s Guide to the EXPLAIN PLAN Part 35: Robust v/s optimal query execution plans

A subset of all possible execution plans can be described as robust. While such solutions are not always quite optimum, they are almost always close to optimum in real-world queries, and they have desirable characteristics, such as predictability and low likelihood of errors during execution.(read more)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 34: SQL Aaargh!

The biggest problem with SQL query optimization is that semantically equivalent SQL queries are not guaranteed to perform equally well. When I encounter problems like this, I sympathize with the folks who got frustrated with RDBMS performance and created NoSQL.(read more)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 33: The mother of all SQL antipatterns?

The mother of all SQL “anti-patterns” is the ad-hoc query. Here, the end-user of the application can specify any combination of parameters—for example, the job_id, the dept_id, or a combination of both—and the data is retrieved using a catchall query.(read more)

OT: Pictures from the NoCOUG winter conference at Oracle HQ

There were 130 attendees at the Oracle conference center on January 27 at the Oracle conference center in Redwood City. There was a fantastic breakfast spread. The registration desk was a marvel of neatness. Delphix sent its most photogenic representative. And so did Cloudera. Andy Mendelsohn’s body language says it all: “Oracle is king of the hill and we’re planning to stay here for a long time.” Andy started at Oracle as a junior (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 32: Pretzels created by someone experimenting with hallucinogens?

In an interview for the NoCOUG Journal, Steven Feuerstein said: “Some people can perform seeming miracles with straight SQL, but the statements can end up looking like pretzels created by someone who is experimenting with hallucinogens.” As if to prove Steven correct, NoCOUG held three international SQL challenges. The winning entries were mind-boggling indeed.(read more)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 31: How to Avoid a Salted Banana

In the February 2015 issue of the NoCOUG Journal, Lothar Flatz introduces the term “salted banana” for a certain kind of problem in SQL tuning.(read more)

OT: Win a free NoCOUG membership for yourself and three friends

You can win a free membership in the Northern California Oracle Users Group (NoCOUG) for yourself and three friends by correctly identifying the colorful objects on the front cover of the winter issue of the NoCOUG Journal and where the picture was taken (or making a good-enough guess). You also have to write a few sentences that capture the meaning of the picture and your experiences with NoCOUG; for example, “NoCOUG conferences offer a lot (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 30: Throw Away That EXPLAIN PLAN! (Part IV)

We tend to overuse the tool—EXPLAIN PLAN in this case—that we are most familiar with. There is an expression—attributed to behavioral scientist Abraham Maslow—that “if all you have is a hammer, everything looks like a nail.” Maslow also tells the story of a drunk searching under a street lamp for his house key, which he had dropped some distance away. Asked why he didn’t look much where he had dropped it, the drunk replied, (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 29: Throw Away That EXPLAIN PLAN! (Part III)

We tend to overuse the tool—EXPLAIN PLAN in this case—that we are most familiar with. There is an expression—attributed to behavioral scientist Abraham Maslow—that “if all you have is a hammer, everything looks like a nail.” Maslow also tells the story of a drunk searching under a street lamp for his house key, which he had dropped some distance away. Asked why he didn’t look much where he had dropped it, the drunk replied, (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 28: Throw Away That EXPLAIN PLAN! (Part II)

We tend to overuse the tool—EXPLAIN PLAN in this case—that we are most familiar with. There is an expression—attributed to behavioral scientist Abraham Maslow—that “if all you have is a hammer, everything looks like a nail.” Maslow also tells the story of a drunk searching under a street lamp for his house key, which he had dropped some distance away. Asked why he didn’t look much where he had dropped it, the drunk replied, (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 27: Throw Away That EXPLAIN PLAN! (Part I)

We tend to overuse the tool—EXPLAIN PLAN in this case—that we are most familiar with. Watch this fascinating YouTube video Rewriting SQL Queries for Performance in 9 Minutes by Stephane Faroult in which he makes a good argument that execution plans should not be the first thing to look at when a query does not perform well. He argues if you write high-quality SQL queries and your tables are well indexed, you can be reasonably (more...)

Repost: Oracle Trivia Quiz

All the answers to the quiz are in the November 2014 issue of the NoCOUG Journal . I am the editor of the NoCOUG Journal. What’s NoCOUG, you ask? Only the oldest and most active Oracle users group in the world. If you have not attended a NoCOUG conference in the last 28 years—yes that’s how long NoCOUG has been around—you can attend the winter conference on January 27 for free subject to availability of free (more...)

OT: Career Advice for Oracle Database Professionals

A strong advocate for women in technology, Kellyn Pot’Vin is an OakTable Network Member and was an Oracle ACE Director until joining a group of Enterprise Manager specialists at Oracle Corporation. She specializes in environment optimization tuning, automation, and creating robust, enterprise-level systems. Kellyn works almost exclusively on multi-TB-sized databases, including Exadata and solid-state disk solutions, and is known for her extensive work with Enterprise Manager 12c and its command-line interface. She is the co-author (more...)

OT: Career Advice for Oracle Database Beginners

Tom Kyte is a Senior Technical Architect in Oracle’s Server Technology Division. Before starting at Oracle, Tom worked as a systems integrator building large-scale heterogeneous databases and applications, mostly for military and government customers. Tom spends a great deal of time working with the Oracle database and, more specifically, working with people who are working with the Oracle database. In addition, he is the Tom behind the “AskTom” column in Oracle Magazine, answering people's questions (more...)

OT: Trip Report: Managing the Largest OLTP Database in the World

At the NoCOUG fall conference at the eBay town hall in San Jose, we got a first-hand look at the workings of the most complex database environments in the world.(read more)

OT: Toad University at NoCOUG fall conference

The NoCOUG fall conference featuring Toad University will be held at the eBay Town Hall in San Jose, CA on Wednesday, November 19. If you have never attended a NoCOUG conference in the 28-year history of NoCOUG—yes, that’s how long NoCOUG has been around—you’re invited to attend the upcoming conference for free. Simply send your name, title, and company to contact_nocoug@nocoug.org.

Toad Overview and Roadmap for DBAs, Developers, and Data Analysts—Daniel Norwood & (more...)

NoCOUG watchers protest despicable tactics being used by NoCOUG management

FOR IMMEDIATE RELEASE NoCOUG watchers protest despicable tactics being used by NoCOUG management SILICON VALLEY (NOVEMBER 13, 2014) – Veteran NoCOUG watchers all over Northern California have been protesting the despicable tactics being used by NoCOUG management to lure Oracle Database professionals to the NoCOUG conference at the beautiful eBay Town Hall next week. Instead […]

OT: Oracle Trivia Quiz

All the answers to the quiz are in the November 2014 issue of the NoCOUG Journal . I am the editor of the NoCOUG Journal. What’s NoCOUG, you ask? Only the oldest and most active Oracle users group in the world. If you live in the San Francisco bay area and have never ever attended a NoCOUG conference in the last 28 years (that’s how long NoCOUG has been around), please contact me for a free (more...)

Oracle Trivia Quiz

All the answers can be found in the November 2014 issue of the NoCOUG Journal. Which executive vice-president of product development at Oracle began as the PL/SQL product manager? (page 23) Which senior vice-president of server technologies at Oracle wrote the B-Tree indexing code back in the day? (page 23) What is the evil twin […]

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 26: Answers to the Final Exam! (Part IV)

The answers to the third problem in Part 22 of this series “We Don’t Use Databases; We Don’t Use Indexes.”(read more)