Oracle Event Tracing

Oracle provides various diagnostic tools for debugging the RDBMS. Certain events can be turned on to dump diagnstic information to trace files. Next, some INIT.ORA parameters are available that can be used while diagnosing memory and disk corruptions. There parameters are not set during normal operation of the database because they affect the performance. But in some circumstances it becomes necessary to turn them on to diagnose the issues with RDBMS, you can think it as extended SQL trace.

Health Check - RAC/DB

Running the following OS commands you can get the Health Check for your cluster and Database, all the output is redirected to one file to analyze.You can run it in a .bat file or separately on the command prompt.

RMAN Duplicate Database from RAC ASM to RAC ASM (11gR2)

Duplicating RAC database is very simple, first duplicate RAC Database to a single instance using RMAN and convert the single instance into a RAC cluster.
Testing Environment:
- Two nodes RAC 11gR2 (11.2.0.3) on Windows 2008R2
- Source RAC Database: TESTRAC (testrac1,testrac2)
- Target RAC Database: DUPDB (dupdb1,dupdb2) on the same hosts where TESTRAC is running
- ASM instances with three diskgroups (DGDUP for dupdb)
- Backup took already (on Netbackup) for Source Database, We CONFIGURE DEFAULT DEVICE TYPE TO SBT_TAPE; for our environment

The clock on host is not synchronous with the mean cluster time (RAC 11g)

Symptoms
Cluster alert log on one of the nodes shows the following message

[ctssd(804)]CRS-2409:The clock on host or-21 is not synchronous with the mean cluster time. No action has been taken as the Cluster Time Synchronization Service is running in observer mode.

OR

[ctssd(9534)]CRS-2409:The clock on host   is not synchronous with the mean cluster time. No action has been taken as the Cluster Time Synchronization Service is running in observer mode.

DG4MSQL - Where clause does not return data

Problem:
One of the customer was facing issue while querying to SQL Server Database using dblink through DG4MSQL.  They have a view on SQL Server side, when they were querying this view with where clause having string in arabic,it did not return data. Although data was available and it could be seen when using query without where clause.
Customer is using 11g (11.2.0.3) RAC - Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production runs on Microsoft Windows 2008, Gateway is running on same  Database machine.

MSQL to MSQL Replication using GG

Prerequisite
Before attempting this post please review the other related GoldenGate posts on the page Other Cateogories for understanding GoldenGate concepts.
Goal
Testing the Oracle Golden Gate for SQLServer to SQLServer real time replication.