Star Schema Optimization in Autonomous Data Warehouse Cloud
Oracle Autonomous Data Warehouse Cloud does not allow to create indexes. Is this a problem for star schemas because no Star Transformation can be used? Or are the required bitmap indexes automatically created? A look under the hood of ADWC. A typical recommendation for star…
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…
Gathering Statistics in the Autonomous Data Warehouse Cloud
Optimizer statistics are essential for good execution plans and fast performance of the SQL queries. Of course, this is also the case in the Autonomous Data Warehouse Cloud. But the handling of gathering statistics is slightly different from what we know from other Oracle databases….
Bloom filters and parallel execution
Today I want to share with you another interesting example of solving performance problem which happened in the database used for Business Intelligence purposes. Users were complaining that the performance in kind of staging database (STGDB) was much better than the production one (PRDDB), even…
Playing with statistics modification hints
How often did you have the situation when performance problem disappeared just after refreshing object statistics? Of course it is nice to solve the problem quickly and simply, but is always better to understand what has exactly happened. Recently I had such a problem and…
Oracle Home Management – part 7: Putting all together
Last part of the blog series… let’s see how to put everything together and have a single script that creates and provisions Oracle Home golden images: Review of the points The scripts will: let create a golden image based on the current Oracle Home save…
Online Statistics Gathering for ETL – Part 2
In the first part we looked at general preconditions for online statistics gathering to work and some restrictions. In this part we’ll take a look at what happens with direct path loads into partitioned tables. Partitioning There are also some points to consider while working…
Online Statistics Gathering for ETL – Part 1
Online Statistics Gathering has been introduced in 12c and is a very handy feature for ETL and batch jobs developers. However the devil is in the detail. There are some points to remember. Let’s take a closer look. Introduction If you are not familiar with…
Oracle Home Management – part 6: Simple Golden Image Blueprint
As I explained in the previous blog posts, from a manageability perspective, you should not change the patch level of a deployed Oracle Home, but rather install and patch a new Oracle Home. With the same principle, Oracle Homes deployed on different hosts should have…