Recently one of my students asked me if there is any correlation between the AU size in ASM diskgroup and parameter db_file_multiblock_read_count. I made some tests but results are very strange. I have 4 same tables, located in 4 different diskgroups: All tables are smaller then a hidden parameter "_small_table_threshold" so table access full on […]
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 […]
Let’s try to migrate database to ASM diskgroup without big maintenance window. I have database and ASM (11.2.0.4) – the database is prepared to migration: We will use recoverable copy of database to migrate to ASM. The first run of this script will create copy of datafile on ASM: Subsequent executions of this script will […]
I have configured two devices for ASM – one with ASMLib and one with UDEV: I have downloaded 11.2.0.4 grid infrastructure binaries and prepared response file: Of course in production environment you have set different groups for security reasons. If you think that you can ignore security, read my articles regarding privilege escalations: https://blog.ora-600.pl/category/oracle/security/ 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 […]
In this article I will show how to change IP address of cluster interconnect. First we have to define new address of the cluster interconnect before we change network settings. And now stop all cluster resources on both nodes Now we can change cluster interconnect ips Now we can start init cluster resources on both […]
In this article I will show how to reconfigure IP addresses in public network for RAC. ` First we have to close all cluster resources This command can hang on stopping ASM. It’s normal, because the resource CRSD is using OCR, which is located on ASM diskgroup. In ASM alertlog you will see errors like: […]
Procedure to convert a standalone database to RAC 11gR2 I have a single-instance database and I want to convert it to RAC with minimum downtime. The first step is to enable RAC option by recompiling the binaries (YOU HAVE TO STOP THE DATABASE FIRST!!!) After this operation I can startup instance and proceed to migration. […]
Add a new node to RAC Check the network configuration for both nodes On the with active cluster, check the network configuration Configure appropriate network devices on the node, which I want to add Create appropriate user on the new node: Configure shared storage – first install ASMLib drivers (if you are using ASMLib :)) […]