UKOUG 2016 DAY 4

Today is the last day at UKOUG in Birmingham; the first session I attended this morning was presented by Julian Dyke about installing and upgrading Oracle 12c release 2 Grid infrastructure and RAC.

He had the possibility to test the installation and upgrade phases at Oracle during 5 days at Oracle last spring. The following tests were done:

single instance : install 12.2.0.1, create database with dbca, upgrade 12.1.0.2 to 12..2.0.1 with dbua

RAC: install 12.2.0.2 grid infrastructure, install 12.2.0.1 RDBMS software, create ASM disk groups (ASMCA), create 12.2.0.2 RAC database (DBCA) , upgrade 12.1.0.2 Grid infrastructure to 12.2.0.1 (gridSetup.sh), upgrade 12.1.0.2 RAC database to 12.2.0.1.

He showed us the main different screenshots describing the installation phases and told us that they did not meet a lot of problems during their installation or upgrade  phases. To upgrade the Grid infrastructure, it is important to run the CVU connected as grid user for example :

runcluvfy.sh -src_crshome=/u00/app/12.1.0.2 -dest_crshome=/u00/app/12.2.0.1
 -dest_version=12.2.0.1 -fixupnoexec

Then after you have the possibility to resolve any issues detected using the generated fixup script.

In his opinion, the use of DBUA is sufficiently robust to use for most upgrades, expecially when the upgrade concerns non critical databases, or databases with fast recovery times or databases on virtual machines. By the way he also mentioned that Oracle is still recommending using scripts for upgrades of large or business critical databases.

He encountered some isssues concerning the upgrade phase for Grid Infrastructure. In particular with the memory_target parameter setting because the ASM and GIMR instances use more memory than in 12.1.0.2, he received the classical ORA-00845 error message. He also encountered problems with invalid objects  and had to extend the root file system of his virtual machine.

Then I attended to Franck Pachot’s session about Statistics Gathering, Best Practices  and Statistic Advisor:

His session described us his findings and recommendations about how to gather statistics, with a lot of technical demonstrations done on the Cloud. A lot of cases were shown, for example volatile tables, preferences for partitioned tables. index gathering statistics.

He showed us the Oracle 12c release 2 statistics Advisor which might be a useful tool, I will check if it is available in Enterprise Manager 13.2.

He finished his by giving us hsi own recommendations: use automatic job for most of the tables, customize the statistics gathering for volatile tables, gather statistics for tables that you load, and important customize the maintenance window for the gathering statistics job.

Finally I wanted to attend at the OEM round table, but unfortunately the session has been canceled :=((

Well,this was a very interesting week with a lot of exchanges and sharing experiences with other Oracle DBA. hope to come back at UKOUG next year !