Category Archives: Databases

Investigate #Oracle #deadlocks

By | May 10, 2018

Sometimes we may end up having some application resources competing for the same resource on our Oracle database. This is usually the case when some exclusive resource must be allocated or updated as in the case of database based locking mechanisms. If there are code issues we may end up in a deadlock situation when… Read More »

#Microsoft SQL Server: Database #Replication (Mirroring) deprecated and replaced by #SQL Availability Groups

By | February 5, 2018

It looks like the Microsoft SQL Database Mirroring a feature I used a lot and for which posted a step by step tutorial that proved to be very popular was deprecated by Microsoft. In a news article on Microsoft site the alternative is presented “Basic Availability Groups (Always On Availability Groups)”. I will summarize in… Read More »

XA datasources with #WebSphere and #Oracle

By | December 5, 2017

When using XA data sources with Websphere and Oracle we must grant to the Oracle user rights to perform XA recovery. STEP 1: Create an XA datasource AdminTask.createJDBCProvider(‘[-scope Node=’+ node +’,Server=’+serverName +’ -databaseType Oracle -providerType “Oracle JDBC Driver” -implementationType “XA data source” -name “‘+jdbcXAProviderName +'” -description “Oracle JDBC Driver (XA)” -classpath [${ORACLE_JDBC_DRIVER_PATH}/ojdbc7.jar ] -nativePath “”… Read More »

#Oracle 12c invisible columns

By | February 20, 2021

“Invisible columns”: This is a new feature introduced in Oracle 12c that got me all excited.In short you can now have hidden columns in a table that are not visible to the standard SELECT, INSERT clauses if you do not want to. Some usage for this: Legacy application queries I hate how you have to… Read More »

Set up automatic #Oracle database back-up using #RMAN

By | September 19, 2017

There is a very easy method of setting up on Linux an automatic back-up for Oracle by using database procedures, RMAN and scripts. STEP 1: Define a back-up script Create in /home/oracle/ a script file with the content: #!/bin/bash export ORACLE_HOME=/home/oracle/app/oracle/product/11.2.0/dbhome_1 export PATH=$PATH:$ORACLE_HOME/bin export ORACLE_SID=prod rman target / CMDFILE=/home/oracle/bin/backup.rman LOG /data/oradata/backuplogs/rman-`date -I`.log exit 0 Where… Read More »