At UKOUG Tech’15 (Super Sunday) there was a session called "12c: A Closer Look at the Multi-Process Multi-Threaded Model for Oracle on Linux/Unix" by Markus Flechtner. Since then I can’t stop thinking about the performance of this feature. Why Oracle decided to provide it? I did some tests regarding sort operations and threaded execution was […]
Let’s check, why PRAGMA UDF makes execution faster, then regular function. C function responsible for calling a PL/SQL code from SQL is called "plsql_run": Now let’s try to create a new HR session and create a simple function which will multiple values by 2: From other terminal I will connect to the HR session with […]
I było tak, że 31 dnia miesiąca sierpnia roku 2015, spotkali się entuzjaści Wyroczni w posiadłości AVIVA. I było tak, że dzierżąc kufle – po brzegi browarem wypełnione – zasiadło wielu aby posłuchać kilku, którzy chcieli się przemyśleniami swoimi podzielić. I stało się tak, że admin przepijał do dewelopera a deweloper do admina i pospołu dyskusja toczyła się wartka a […]
One of the new CBO features in database 12c is "sql plan directives". The main purpose of this functionality is to deliver better adaptive plans if object statistics does not reflect the reality. Quoting after documentation During SQL execution, if a cardinality misestimate occurs, then the database creates SQL plan directives. During SQL compilation, the […]
At the beginning we have to prepare parameter file for the new instance Start the instance in nomount Since I want to duplicate the database in active mode I will register it in LISTENER. To achieve this I have to add the following lines to the listener.ora Now we can perform active database duplication with […]
There is a new feature in Oracle Spatial 12c, called "Spatial Vector Acceleration". According to Oracle: One of the most notable improvements with Oracle Spatial and Graph 12c can be seen in performance increases in vector data operations. Enabling the Spatial Vector Acceleration feature (available with the Spatial option) dramatically improves the performance of commonly […]
There is a great new feature related to the 12c database. The feature that will resolve a lot of problems with migrating databases between endian formats. And thanks to our new partner – Omnitec, who agreed to share with their SPARC resources – I will be able to demonstrate you this powerful solution. Oracle has […]
There are a lot of new powerful features in the 12c database but don’t forget about the little features that can make a DBA happier on the day to day basis 🙂 One of my favourites is a new approach to use a DBCA command line interface to create a database in silent mode: Nice, […]
One of my customers had a problem with a very slow TRUNCATE TABLE operation on a partitioned table having 22 000 partitions. The problem has raised after a test migration to database 12c. I’ve prepared a little demo to address this issue and show the walkaround for it. Oracle Database 12c (12.1.0.2): Oracle Database 11g […]