Category Archives: Databases

Fix #DB2 Communication protocol failed to start issue: SQL5043N

By | November 21, 2017

I moved my DB2 installation to a new server from a full back-up. After performing all the necessary steps: 1. Recreate the necessary users: db2inst1, db2fenc1, db2das1 2. Give ownership to their home directories ISSUE: I tried to start the instance. I logged in to the db2inst1 user and started the database. This was the… 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/backup.sh 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 »

Validate and Investigate a live #DRBD replicated Oracle Instance using LVM clone

By | October 19, 2017

This is another post related to the DRBD replication setup I describe in post #DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6. Sometimes we need to be able to mount the offline replicated Oracle database instance for investigations. This can be done by using logical volume snapshots.… Read More »

Debug tools for enterprise environments

By | February 8, 2017

There are various tools that I use to spot issues and investigate an enterprise environment. One of my favourite tools is IBM Performance Analysis Suite. Capabilities described by IBM: Import all kinds of performance data for analysis. Some examples: DB2 snapshot, Java verbose GC output, Java thread dumps. Import software/middle-ware configuration for compliance checking. Some… Read More »

DB2 : Errors when a database nickname or view is no longer available

By | February 8, 2017

In an enterprise application based on hibernate running over DB2 we have to refer with several views and nicknames to external tables. This can be the case when SSO is used or there are some common static data (accounts, user entries, financial constants etc. ) that are kept in a centralized database repository and are… Read More »

Blog Links: Oracle Trace File Analyzer (TFA)

By | February 8, 2017

One of the best introduction tutorial I have seen about a useful tool set. I am sick of all the empty marketing “pitches” I see daily. Oracle Trace File Analyzer (TFA) – An Overview Guide A must read for anyone that has to work with Oracle DB and needs to do a deep investigation of… Read More »

Oracle: Reactivate a database user

By | February 8, 2017

I am always very annoyed when my Oracle user is automatically expired and locked. This is done automatically at 180 days in some installations. The following are some very easy steps for a question that everybody is asking again and again on forums. STEP 1: Connect to the DB sqlplus / as sysdba STEP 2:… Read More »