Oracle 12.2 PDB Migration mit dem DataGuard-Broker – „DataGuard on PDB level“
This post was originally published on this siteMit Oracle 12.2 kann der DataGuard-Broker beim Verschieben einer Pluggable Database von einer Container-Datenbank in eine andere helfen. Je nachdem ob die Ausgangsdatenbank eine Primär- bzw. Standby-Datenbank ist, nennt Oracle das Verfahren „PDB Migration“ bzw. „PDB Failover“. Etwas…
CDB Views and Query Optimizer Cardinality Estimations
This post was originally published on this siteToday I faced a performance problem caused by a bad cardinality estimation involving a CDB view in a 12.1.0.2 multitenant environment. While solving the problem I did a number of observations that I try to summarize in this…
Announcing participants in Oracle Dev Gym SQL Championship 2017
This post was originally published on this siteAnother year, another Oracle Dev Gym SQL Annual Championship. Woohoo! Players have exercised their mental muscles with the SQL puzzles throughout 2017. Congratulations to everybody digging in all year, trying to figure out the pretzelbenders of me and…
Oracle Enterprise Manager Audit
This post was originally published on this siteWhy you should read this blog post? You need to take care of the Audit function from OEM CC even if you don’t want to use it. It’s enabled by default and needs to be managed! Housekeeping for…
How Well a Query Optimizer Handles Subqueries?
This post was originally published on this siteAt the beginning of December, at the UKOUG Tech17 conference in Birmingham (GB), I presented a comparison of the query optimizers of MySQL 8.0.3 and PostgreSQL 10.1. One of the things I talked about is their ability to…
Roleplaying Dimensions and SSAS Multidimensional
This post was originally published on this siteYes, I can hear you, SSAS Multidimensional is so old and unsexy. Still, a lot of the data warehouse projects I work on still use this techonology. So what is a roleplaying dimension? It’s quite simply a dimension,…
Object type “nested” implicit grants
This post was originally published on this siteA colleague got an “ORA-01720: grant option does not exist” error and couldn’t understand why. So together we researched a bit and learned some things about how object type grants across schemas works – including a small surprise…
Hunting date errors
This post was originally published on this siteJust recently, I had to find out, why a dataload, that had been working smoothlessly in the past, suddenly prodced an error. The data is coming from an ORACLE database, and imported into MS SQL Server with an…
SQL Server Graph Database and Performance
This post was originally published on this siteWhen Microsoft announced, that their upcoming release would contain an implementation of Graph Database objects, I was intrigued. There are already a couple of good posts around, that explain how to use the feature, e.g. how to create…