Polymorphic Table Functions (PTF) , Part 3 – Row Replication
In the third part of the PTF-series we learn how a PTF can change the cardinality of the input data flow: return more or less rows as in the input. We’ll use the same simple table as in the part 2 and our new task…
Online Statistics Gathering for ETL – Part 3
Preparing my session on Online Statistics Gathering for ETL for the DOAG conference, I noticed some points that I didn’t covered in the previous two blog posts. The first point is showing the problem that may arise if indexes are involved. The second one is…
Polymorphic Table Functions (PTF) , Part 2 – More Basics With Some Deep-Dive
In the first part of PTF series we went through a very basic example removing some columns and adding a new column with a constant value. Starting from the same example we’ll do something more meaningful in the second part. How about concatenating the values…
Polymorphic Table Functions (PTF) – Tinkering with Rowsets
Writing the second „basics“ post on PTF I discovered, that there were much more details worth mentioning, than it would be acceptable for a „basics“ post and would blow it up anyway 😉 So I decided to to separate the tests and finding in this…
Polymorphic Table Functions (PTF) , Part 1 – Basics
I have already posted some examples on Polymorphic Table Functions in Oracle 18c in the last months. I quickly realized how difficult it is to explain completely new feature using advanced examples and wanted to write a series of posts starting from very basics. Now…
10 Tips to Improve ETL Performance – Revised for ADWC
The Autonomous Data Warehouse Cloud (ADWC) is a self-configuring, fast, secure and scalable platform for data warehouses. Does this mean we don’t have to take care anymore about performance of our ETL processes? Which performance tips are still important for us, and where can we…
SQL Magic Squares – or Why the Optimizer does not like Magic
A long-time player at the Oracle Dev Gym tried his hand at generating Magic Squares using SQL. When he attempted to tune his statement a bit, he was surprised that it didn’t go a little faster as expected, rather it went from 2 minutes to…
String to DATE conversion and validation in 12.2
A new little feature in Oracle Database 12.2 is, that you can convert strings to dates without worrying about exception handling. (That goes also for converting to numbers or timestamps or other datatypes, but here I’ll concentrate on dates.) It’s just one of a ton…
A handful of articles
A little while ago a member of the Danish Oracle User Group DOUG asked if anyone had a bit of experience with use of R together with Oracle Database. I remembered an article I wrote for OTech Magazine on forecasting with R and Oracle and thought…
Row pattern matching nested within hierarchy
I’ve been playing around with MATCH_RECOGNIZE – the data pattern matching extension to SELECT that was introduced in version 12. Most examples I’ve seen have used the default AFTER MATCH SKIP PAST LAST ROW as most often the logic dictates, that when we have found…