Direct-Path INSERT is a very efficient way to load data into data warehouse tables. The load performance can even be improved with NOLOGGING on the target table. In Oracle 12c Release 2, this is even possible for Oracle Data Guard environments. But is it a good idea?
Incremental statistics reduce the time to gather global statistics for a partitioned table. Really? In some situations it may happen that incremental statistics slow down statistics calculation dramatically. An example of a real project in Oracle 12.1 and how it can be improved with Oracle 12.2.
This year, I had the opportunity to present three sessions at the DOAG conference in Nuremberg – one on each conference day. Here a short summary of the sessions and links to the downloads.
Hash keys are often used as primary keys in Data Vault environments. When loading dimensional data marts from a Data Vault schema, it seems to be obvious to use them as dimension keys, too. At least in combination with Oracle Database In-Memory, this is not a good idea.
Analytic Views, in combination with Attribute Dimensions and Hierarchies, are very useful for ad-hoc queries in a Star Schema. But how about the performance of this Oracle 12.2 feature? I wanted to know it and analyzed the execution plans of some simple queries.
In summer time, the nights are very short. For some Data Warehouses, this is the case all year round, but not because of late sunset and early sunrise. The night is not long enough to finish all the ETL jobs. Long-running load jobs that run for several hours are not a seldom situation. Here some tips how this can be avoided.
On 13 and 14 September 2017, the Trivadis Performance Days 2017 will take place in Zurich. As in previous years, it will be an exciting event for everybody interested in Oracle performance features. For me, it will be a very special adventure this year.