Generate AWR Snapshot Manually

Automatic Workload Repository (AWR) is a collection of database statistics owned by the SYS user. By default snapshot are generated once every 60min .

But In case we wish to generate awr snapshot manually, then we can run the below script.  This is usually useful, when we need to generate an awr report for a non-standard window with smaller interval.

Lets say, we want to generate a report for next 15 minutes. (12:10 – 12:25) . So we will generate a snapshot at 12:10 and another at 12:25 .

SRVCTL (Server Control utility) commands in Oracle

srvctl commands – 12c

• To manage Oracle ASM on Oracle Database 12c installations, use SRVCTL in the Oracle Grid Infrastructure home for a cluster (Grid home). If you have Oracle RAC or Oracle Database installed, then you cannot use SRVCTL in the database home to manage Oracle ASM.
• You cannot use this command when OCR is stored in Oracle ASM because it will not stop Oracle ASM. To stop Oracle ASM you must shut down Oracle Clusterware.

ORA-235 – Controlfile error !

In our environment, the archives get shipped, applied and are deleted along to make free room inside the FRA for the incoming archives from the primary database resulting massive access and update in controlfile header.
So I noticed something peculiar in the alertlog.
Error ORA-235 occurred during an unlocked control file transaction.  This 
error can be ignored.  The control file transaction will be retried. 

Database Terminated With ORA-27300/ORA-27301/ORA-27302/ORA-27303

Hello friends, so again I faced some issue after creating a new database using DBCA and using RMAN duplicate, so here is my observation and solution to the issue

Cause :

1] During the DBCA execution the permission of the oracle executable in the $ORACLE/bin/oracle has changed from oracle:oinstall to the owner of the asm disk i.e . oracle: asmadmin

-rwsr-s--x 1 oracle asmadmin 385832552 Mar 27 23:49 oracle

(There will be a possibility that the $ORACLE/bin/oracle retains the permission as oracle:oinstall after patching )

Oracle 19c Architectural components Part 3

Oracle Background Processes

Background processes are part of the database instance and perform maintenance tasks required to operate the database and to maximize performance for multiple users. Each background process performs a unique task, but works with the other processes. Oracle Database creates background processes automatically when you start a database instance. The background processes that are present depend on the features that are being used in the database. When you start a database instance, mandatory background processes automatically start. You can start optional background processes later as required.

Mandatory background processes are present in all typical database configurations. These processes run by default in a read/write database instance started with a minimally configured initialization parameter file. A read-only database instance disables some of these processes. Mandatory background processes include the
Process Monitor Process (PMON), Process Manager Process (PMAN), Listener Registration Process (LREG), System Monitor Process (SMON), Database Writer Process (DBWn), Checkpoint Process (CKPT), Manageability Monitor Process (MMON), Manageability Monitor Lite Process (MMNL), Recoverer Process (RECO), and Log Writer Process (LGWR).

Oracle 19c Architectural components Part 2

System Global Area

Oracle 19c SGA

The System Global Area (SGA) is the memory area that contains data and control information for one Oracle Database instance. All server and background processes share the SGA. When you start a database instance, the amount of memory allocated for the SGA is displayed. The SGA includes the following data structures:

Oracle 19c Architectural components Part 1

An Oracle Database consists of at least one database instance and one database. The database instance handles memory and processes. The database consists of physical files called data files, and can be a non-container database or a multitenant container database. An Oracle Database also uses several database system files during its operation.

Oracle 19c architecture oviewview

Oracle 19c Features.

Oracle Database 19c, is the long term support release of the Oracle Database 12c and 18c family of products, offering customers Premier and Extended Support through to March 2023 and March 2026 respectively. It is available on Linux, Windows, Solaris, HP/UX and AIX platforms as well as the Oracle Cloud. Oracle Database 19c offers customers the best performance, scalability, reliability and security for all their operational and analytical workloads.

Installation and Upgrades

• RPM Based Installation  install Oracle 19c Database using RPM method
• Simplified Image based installation of client as well
• Auto Upgrade Utility for Oracle Database
• Docker Container for Oracle 19c
• DryRun mode for GridSetup in clusterware Installation

Introduction to Oracle GoldenGate

Oracle GoldenGate Concepts and Architecture

Oracle Goldengate supports the replication of data across various heterogeneous platforms. The Goldengate replication topology includes the capture and transfer of the extracted data from the source database, across to the destination database.

Below are the topologies which can be used to fulfill various data transfer requirements using data replication.

Golden Gate Replication Configuration

Oracle GoldenGate is a software product that allows you to replicate, filter, and transform data from one database to another database.
It enables the replication of data between Oracle databases and other supported heterogeneous databases.

Golden Gate Architecture

GoldenGate components

• MANAGER
• EXTRACT
• TRAIL
• REPLICAT
• PUMP
• CHECKPOINT
• COLLECTOR