A little over a year ago we have ventured into mathematical foundation of relational theory. From algebraic geometry perspective relations were viewed as Finite Varieties. In the followup exposition we were able to describe functional dependencies via explicit analytic formulas. In this article we shift the focus from varieties to dual algebraic object — [polynomial] ideals.
You know that if we want to execute another script from the current script directory, we can call it through @@, but sometimes we want to know the current path exactly, for example if we want to spool something into the file in the same directory.
Unfortunately we cannot use “spool @spoolfile”, but it is easy to find this path, because we know that SQL*Plus shows this path in the error when it can’t to find @@filename.
So we can simply get this path from the error text:
Supposing you've got data as a text string with "row" and "column" delimiters and you would like to parse out those columns and rows. The external table syntax would actually be great for this, but that requires writing the text out to a file first, and then you can import it back again as columns and rows. There are various other alternatives using SQL and/or XML manipulations, but one method that I don't see much used is to use the Data Cartridge functionality to in a sense expand the SQL language to do this.
In my last post, I wrote about a dream of a European version of ODTUG Kscope conference - working title "Escope." ;-) We're trying to determine whether it would be feasible to create such a conference - if you haven't already, go and fill out the survey and help us find out if there's basis for the dream.
The heart of row pattern matching is finding which row matches what part of the pattern. Within the 12c MATCH_RECOGNIZE clause, DEFINE lists the conditions a row may meet; it doesn't always work the way you expect, especially if you use aggregates in the condition.
This how you install SQL Developer on Mac OS Yosemite. The first thing you need to do is download and install Java 8, not Java 7 on your Mac OS Yosemite as suggested on some web sites. You can determine whether or not Java is installed by running the following command: