In my last post, I’ve challenged you with a quiz about package dependency. The question was about when a dependent object will be invalidated by Oracle when the package on which it depends is recreated.
Just a quick tip for today. Oracle allows us to create special kind of indexes on columns containing long texts. One of them is the CONTEXT type. You don’t need any particular privileges to create an index of this type (other than being able to create indexes in you schema). At least, that’s what the documentation says.
There was a question about creating a CONTEXT index on StackOverflow:
The goal of this article is to provide a quick introduction to Python’s unit testing module called unittest. It is the essence, the very basic information you need to quickly start unit testing in Python.
Introduction to the unittest Module
Key points about unit testing in Python:
modules with tests should import unittest module,
tests should be defined inside a class extending the unittest.TestCase class,
every test should start with the test word,
if a test has a doc. comment (between a pair of ''', i. e. three apostrophes), the comment will be printed when the test is being run (if verbose mode was set),
tests can have setUp and tearDown methods – those methods will be called, respectively, before and after each of the tests; there are also class-level set up and tear down methods,
to execute the tests when the module is run, unittest.main() should be called,
to see which tests are called with additional info, the -v (verbose) parameter should be specified when the module with tests is executed.
Returning a BLOB from a Java Method Embedded in a Database
You’re about to learn your future
Oracle supports embedding Java classes in its database. Different SQL types are mapped to corresponding Java classes to allow us to make the most of this feature. Author of the following question on StackOverflow:
had an issue with returning a BLOB object from Java method back to PL/SQL context. In the beginning, I didn’t even think you could return a new BLOB object from an embedded class. Fortunately, there was a BLOB in my Java, too. Continue reading →
Getting the Top-N Records From an Ordered Set & The New Row Limiting Clause – 11g & 12c
and a cup of tea if you’re lucky
I bet my cup of raspberry-juiced black tea that, somewhere along your journey with Oracle, you had to write a query which was supposed to return only the top-n rows from an ordered set. Unlike some of the other databases, MySQL, for instance, Oracle does not provide a dedicated solution to this problem.
At least, not before the 12c hit the stage.
Before I introduce you to the nice Row Limiting Clause, let me show you why the first solution that comes to mind to solve the problem at hand, in Oracle’s versions prior to 12c, is not the right one, and what voodoo tricks one has to perform to achieve the expected result. Continue reading →
Why did the chicken cross the road?
Because 1 > NULL AND cross_the_road()…
I bet you have heard about the chicken and you know at least a dozen reasons why it had crossed the road. I wouldn’t bet, though, that you have heard about the three-valued logic. And this one is interesting, it even makes the chicken cross the road. The answer to the above question could also be given as: Because it (the chicken) didn’t short-circuit evaluate. What does it all mean? Continue reading →