In topic, I will descript how Oracle handle once we revoke tablespace quota from user. Once blocks assigned to a segment, even after revoked the Tablespace quota and deleted records from table, all allocated block will remain mapping with segment until we released block by using Shrink.
This is the one good reason to release the space once we delete lots of records from a segment.
Sep 18 2020
After Revoked Tablespace Quota From User in Oracle
Sep 02 2020
Unused or Drop Column? Which option should use?
Sometimes DBA got request to drop the table’s columns. Oracle has following options to complete this task.
- Logical Delete.
- Physical Delete.
- Claim space for logical delete columns.
- Claim space for Physical delete column.
- Conclusion.
In this article, I will discuss which option is more appropriate for big size of table. For small table, even physical delete will not take take much time or resource.
Continue readingSep 01 2020
Oracle RAC Cache Fusion
Until Oracle 8i released, Oracle Introduced Parallel Server on Oracle 6i version. Oracle Introduced Real Application Cluster concept on Oracle 8i version. Oracle Cache Fusion is one of the important component in Oracle RAC environment.
- What is Cache Fusion
- How Cache Fusion works?
- How Oracle RAC read block from disk or buffer of another Instance using Cache Fusion?
- How Oracle RAC maintain blocks in buffer across the cluster for DML?
What is Cache Fusion:
Oracle RAC has two or more instances, and it uses Cache Fusion to smoothly move data blocks between these instances’ buffers across the cluster connection. If one instance reads a data block from the disk and another instance needs the same block, it’s faster to grab it from the instance that already has it in its memory (SGA) than reading from the disk again. This quick transfer across the network is way faster than dealing with the slower disk operations, making Oracle RAC work better.
Continue readingAug 30 2020
Oracle Database 19c Installation On Oracle Linux 7.1
I will describe the installation process of Oracle 19c (19.3) Database on Oracle Linux 7.1 on VM.
- 1. Create VM.
- 2. Software Download.
- 3. Install Oracle Linux 7.1 on VM.
- 4. Oracle Database Installation Prerequisites.
- 5. Oracle Database Software Installation.
- 6. Create a Container Database Using DBCA.
- 7. Create a Non-container Database Using DBCA.
- 8. Create Database using SQL Command.
- 9. Post Installation.
Aug 24 2020
How to Rename Ethernet Interface to eth0 in Linux on VM
Sometime you may need to change the Network Interface Name on your system. I faced issue while I was cloning a node to prepare a new node for RAC Environments on Oracle Linux 6.5.
When you clone a VM, you need to reassign the Network device means it will assign new UUID for the device and it will create new Network Interface at OS level. But For RAC, You need to set same name of Network Interface for all nodes. I got below error while was trying install GI (Grid Infrastructure) with different Network Interface Name.
Continue readingAug 18 2020
Copy Password File From Primary ASM to Standby ASM on Oracle 12c
If create a database using DBCA, usually password file create on ASM Diskgroup. For RAC, this is also recommended to use ASM Diskgroup for spfile and password file. In this topic, I will show how to copy password file from ASM of Primary database to Standby on ASM.
Password File location on Primary Database:
[oracle@ocmnode1 ~]$ . oraenv ORACLE_SID = [ORCL1] ? +ASM1 [oracle@ocmnode1 ~]$ asmcmd pwget --dbuniquename ORCL +DATA/ORCL/PASSWORD/pwdorcl.256.1048094823Continue reading
Aug 13 2020
Unable To Load Module Oracleasm in Oracle 12c
CRS (Cluster Ready Service) is not starting and getting ‘FATAL: Module oracleasm not found’ error on log files.
[root@ocmnode1 ~]# cat /var/log/messages
Aug 12 01:32:08 ocmnode1 modprobe: FATAL: Module oracleasm not found.
Aug 12 01:32:33 ocmnode1 modprobe: FATAL: Module oracleasm not found.
Aug 12 01:34:32 ocmnode1 modprobe: FATAL: Module oracleasm not found.
After checked in details found that oracleasm package / RPM was not working.
[root@ocmnode1 ~]# oracleasm init Creating /dev/oracleasm mount point: /dev/oracleasm Loading module "oracleasm": failed Unable to load module "oracleasm"Continue reading
Aug 09 2020
Migrating OCR, Voting Disk and MGMTDB to another ASM DiskGroup in 12c RAC
Sometime DBA need to move or migrate below mentioned files or DB to different ASM DiskGroup for difference reason. I will show how to move or migrate below mentioned files or DB from one ASM DiskGroup to Another:
- How to move or migrate OCR and Voting Disk from one ASM Diskgroup to another.
- How to move or migrate SPFILE and PWDFILE from one ASM Diskgroup to another.
- How to move or migrate MGMTDB from one ASM Diskgroup to another.
Aug 08 2020
Adding a Node to Oracle RAC 12c
Complete below list of tasks:
DBA may need to add a new node or existing node (which got deleted from cluster) into Clusterware.
List of tasks for New Node:
- Install same version of OS
- Setup environment variable
- Install all required package including Oracleasm
- Configure Networking (IP and others)
- Check Time Synchronization
- Change Recommended Kernel Parameters for Oracle
- Create Group and User (make sure these are same with existing Nodes)
- Setup SSH configuration for grid user or (user which was used for GRID installation) between new node and other nodes.
Aug 01 2020
Deleting a Node to Oracle RAC 12c
A node in the cluster may crash due to hardware or OS problems and is not recoverable. So DBA needs to delete a problematic node from clusterware. In this topic I will show discuss how to delete a node from two nodes RAC.
Two Nodes: ocmnode1 will be deleted
- ocmnode1
- ocmnode2
Deinstall Oracle Home:
Continue reading