Search

Top 60 Oracle Blogs

Recent comments

September 2015

The Hitchhiker’s Guide to the EXPLAIN PLAN Part 40: Why is it so hard to get SQL performance right the first time?

In the August 2015 issue of the NoCOUG Journal, we asked Stéphane Faroult why it is so hard to get SQL performance right the first time. His answer implies that SQL itself and the way it is taught are the problems.(read more)

Friday Philosophy – If You are reading this You are probably Pretty Smart

I bet I can predict a few things about you. And I mean You, the person reading this on my Blog right now.

At senior school (when you were aged between 11 and 16-ish) you were at the top of your classes. At least most of them. You were in the top few in your year for most science subjects and probably Maths too.

And you were not bad at any of your subjects once you had a choice over them, but there was at least one subject you were glad to get rid of as you were poor at it. But if you think back, I bet you were simply *almost average* at it, there were as many kids or more worse at it than you then there were better than you at it. You were just not as stand-out good as you were in other subjects. Come on, I’m right aren’t I? Even your poor subjects you were OK at compared to all the other kids.

Longer strings in 12c

Most people are now aware that in 12c, a VARCHAR2 has been extended from a maximum size of 4000 to 32767 bytes.

Similarly, there’s many a note/blog post etc about needing to set the following parameter to enable it:


SQL> alter system set max_string_size = EXTENDED scope=spfile;

System altered.

and then bounce the database. But its important note that its NOT just as simple as that. Here’s what will happen if you only do that

Oracle OpenWorld : It’s just around the corner…

The total insanity that is Oracle OpenWorld 2015 is just around the corner. I’ve got my flights and hotels booked, so I think I’m good to go!

The first couple of days will be ACE Director briefings. The big announcement this year will be the Oracle Games Cloud (#OGC), but as a beta program participant I’m under NDA so I’m not allowed to talk about it. It will be interesting to see what else is coming down the pipeline. I expect lots of hardware refreshes and standard stuff like that, but there is always something unexpected that makes you sit back…

VirtualBox 5.0.4

virtualboxVirtualBox 5.0.4 has been released.

It’s a maintenance release, with a whole bunch of bug fixes. Downloads and changelog in the usual places.

The “Check for Updates…” link from the menu hasn’t noticed the upgrade yet, so if you are keen you will have to download it manually. :)

Happy upgrading…

Cheers

Tim…

 

SQL and the Art of Problem Solving

What would you do if you were lost in a labyrinth of underground caves? In the dark. With no food. Mark Twain tells the story of how Tom Sawyer and Becky Thatcher got separated from their picnic group and got lost in a labyrinth of underground caves. What’s that got to do with problem solving? I think that the first rule of problem solving is “If at first you don’t succeed, try, try, again.” Of course, there’s more to problem solving than determination. In his 1945 book “Solve It!”, one of the 20th century’s most notable mathematicians, George Polya, said: “If you cannot solve the proposed problem try to find first some related problem. Could you imagine a more accessible related problem? A more general problem? A more special problem?

Viewing Figures

I’ve just realised that I haven’t been paying any attention to the number of visitors I’ve had over the last few months, so I missed the moment when I reached the next half million.  The count has now reached 4,571,856 – probably hitting 4,500,000 around July 6th – so it’s time to do another of my little summary pages to see if new topics have become important and old topics have faded to insignificance.

In fact, the top five remain virtually unchanged, though 4th and 5th places have swapped over.

#Oracle Learning Streams – Have a look!

Oracle University has introduced a new format that suits the way many learn today: Oracle Learning Streams

Oracle Learning Streams

Although I do not expect that this format will replace classroom training, I consider it a great enhancement – coming with a price like most good things…

As you can see, I’m happy to contribute to it in my area of expertise: You can find me here in the Database Stream.

Friday Philosophy – On “Being the Expert”

Working as a recognised expert at something is a little…strange, I find.

I had an assignment this week to go visit a client, have a look at a performance issue and find out the root cause. I was also to at least come up with suggested resolutions with the ideal aim of giving them a proven fix they could implement. All to be done in two to three days. This is pretty standard fayre when you are putting yourself forward as some sort of expert in something. And it is not always an easy thing to do – for more reasons than you might expect.

Measuring Tuxedo Queuing in the PeopleSoft Application Server

Why Should I Care About Queuing?

Queuing in the application server is usually an indicator of a performance problem, rather than a problem in its own right.  Requests will back up on the inbound queue because the application server cannot process them as fast as they arrive.  This is usually seen on the APPQ which is serviced by the PSAPPSRV process, but applies to other server processes too.  Common causes include (but are not limited to):