You have to download the 3rd party JDBC driver and point SQL Developer to it. You can read how to do it here.
Update: My colleague just told me this.
“If you at any point decide to use Windows authentication to connect (like I just did), you might hit this error:
Status : Failure -I/O Error: SSO Failed: Native SSPI library not loaded. Check the java.library.path system property.
Averaging a collection of values by computing the mean is an operation learned in elementary school. Sum the values. Divide by their quantity. Many learn the process by rote, with little attention given to how the result might be used and when it might or might not be appropriate.
Consider the problem of computing the average miles per gallon (mpg) across a fleet of automobiles. We have some number of vehicles. We know the miles per gallon each is capable of. We presume each vehicle will be driven about the same number of miles. We want to improve fuel economy across the fleet. We decide to compute a mean miles per gallon to give a single number by which to track our improvement.
Example Data: Download and execute harmonicExamples.sql to create the example tables and data used in this article.
Median is a measure of central tendency useful in describing the typical experience, or the typical case. It's a type of average along with the mean, but less susceptible to skew from outlying values. Mean is useful when you need the math to work out, such as when you want your average daily sales to sum to your total monthly sales. Median is useful in describing, say, what the typical sale looks like, or what the typical customer is likely to spend.
Oracle Database implements a family of STDDEV functions for computing the standard deviation from the mean. If you think of the mean as beginning to paint a picture of the underlying data, then standard deviation is another brush-stroke toward a fuller picture that will help you draw meaning from the data you're studying.
The video of the online chat that I had with Grant Fritchey about statistics in SQL Server and Oracle is now online. It went pretty well – according to the stats 537 people attended, although the peak concurrency I noticed was only 467 – of which there were still over 400 after an hour and a quarter.
At the start of the event, James Murtagh put up a quick poll to see how many attendees used SQL Server, how many used Oracle, and how many used both. There’s a degree of bias in the results, no doubt due to the self-selecting nature of the event, but I thought the results were interesting:
AVG is an aggregate function in SQL to compute the "average" of a set of values. More precisely, it computes the mean of those values. And even more precisely, AVG computes what is known as the arithmetic mean. The underlying math is so deceptively simple, it's easy to believe one understands the result and how to apply it. But keep reading! Learning about "average" is like uncovering an iceberg. There's more to it than meets the eye.
SQL Statistic Series: You are reading part of an ongoing series covering the statistical functions available in the Oracle Database implementation of SQL.
Updated 22nd Jan
I’ve previously advertised the fact that the latest online discussion that Red Gate has arranged for me to have with Grant Fritchey will be on 23rd Jan and we will be talking about statistics. If you’ve listened in to any of these talks in the past you’ll realise that they are completely unscripted; what you get is a couple of guys in a (virtual) pub comparing and contrasting their favourite database engines and trying to learn a little bit about how the other technology works.
Here’s a question on OTN from a SQL Server user that should prompt a few interesting ideas. Re-arranged and paraphrased it goes something like this:
In SQL Server I can write the following code:DECLARE @Counter INT SELECT @Counter = 0 UPDATE TempDB.dbo.TransactionDetail SET @Counter = AccountRunningCount = @Counter + 1 FROM TempDB.dbo.TransactionDetail WITH (TABLOCKX)
What I want to do is more like this:DECLARE @Total INT = 0 UPDATE StringOutput set @Total = SumOfLength = @Total + ColLength OPTION (MAXDOP 1)
How do I do something similar in Oracle ?
After the success of the last Oracle/SQL Server discussion, James Murtagh of Redgate has arranged another online discussion – this time about the different ways in which temporary tables are implemented and used. As before I’ll be doing the Oracle bit and Grant Fritchey will be doing the SQL Server bit.
Update: Now that the event is over, you can listen to the recording at this URL.
When preparing for the the IOUG Collaborate 12 deep dive on deploying Oracle Databases for high Availability, I wanted to provide some feedback on what hardware components are failing most frequently and which ones are less frequently. I believe I have reasonably good idea about that but I thought that providing some more objective data would be better. I couldn’t find and results of a more scientific research so I decided to organize a poll. This blog post shows the results and I promised to share it with several groups.