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Category Archives: Database management

Clemens Bleile

sqlplus and its column output

By | Database Administration & Monitoring, Database management | No Comments

During tuning or normal DBA activities one of the most annoying things is sqlplus with its default column output when running queries. I.e. even after setting a linesize of 1000 and a pagesize of 1000 the output may look as follows in your preferred terminal emulation (putty here): Most people address this by using other tools like sqldeveloper (or sqlcl with sqlformat ansiconsole). However, a lot of people still use sqlplus. How can you address…

 
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Joël Cattin

PostgreSQL – logical replication with pglogical

By | Database Administration & Monitoring, Database management, Postgres | No Comments

Although PostgreSQL 10 integrate native logical replication (have a look here or here), it is always interesting to be aware of alternative solutions to the available in-core features. One of those is called pglogical. It’s a Postgres extension developed by 2ndQuadrant, major contributor to PostgreSQL development. The goal of this blog post is to discover how to install pglogical and configure it in order to generate simple logical replication cases. Installation To get the extension…

 
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Clemens Bleile

Connect-times to the DB suddenly become very slow using sqlcl

By | Database Administration & Monitoring, Database management, Development & Performance, Oracle | 2 Comments

I recently wrote a couple of sql-scripts which had to run on all of my customer’s DBs. The sql-scripts had to be started from a Linux-client, which does not have any Oracle client software installed. So I thought of using sqlcl (see http://www.oracle.com/technetwork/developer-tools/sqlcl/downloads/index.html), because there is no need to “install” something then. All I needed was an installed JRE on the Linux-machine. Fortunately that was available. So I downloaded the newest version of sqlcl and…

 
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Nicolas Penot

Migrate Oracle Database(s) and ASM diskgroups from VMWARE to Oracle VM

By | Database Administration & Monitoring, Database management, Hardware & Storage, Oracle | No Comments

This is a step by step demonstration on how to migrate any ASM disk groups from a cluster to another. May be use, with or without virtualization and may be used with storage layer snapshot for fast environment provisioning. Step 01 – Shutdown source database(s) on VMWARE servers Shutdown all databases hosted in the targeted Disk groups for which you want consistency. Then unmount the disk groups. $ORACLE_HOME/bin/srvctl stop database -db cdb001 $ORACLE_HOME/bin/asmcmd umount FRA…

 
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Clemens Bleile

CPUs: Cores versus Threads on an Oracle Server

By | Database Administration & Monitoring, Database management | 2 Comments

When doing a performance review I often do talk with the DBA about the CPU utilization of the server. How reliable is the server CPU utilization with tools like top or the host CPU utilization in the AWR-report? E.g. on an Linux Intel x86-64 server with 8 Cores and 16 logical CPUs (Intel Hyperthreading), what does a utilization of 50% mean? As I had an ODA X7-M in a test lab available, I thought I’ll…

 
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Marc Wagner

RMAN debugging during catalog import

By | Database management, Oracle | No Comments

In this post I would like to share how I have been able to troubleshoot and solve a catalog import issue using RMAN debug function. As we can see, the error message provided by RMAN is not very helpful. oracle@vmtestoradg1:/home/oracle/ [RCAT12C] rman catalog rcat/manager Recovery Manager: Release 12.2.0.1.0 connected to recovery catalog database RMAN> import catalog rcat/manager@RCAT11G; Starting import catalog at 05-JAN-2018 14:11:45 connected to source recovery catalog database RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE…

 
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Marc Wagner

ORACLE 11g to 12c RMAN catalog migration

By | Database management, Oracle | 2 Comments

This is a small migration demo of a 11g catalog (RCAT11G) to a new 12c catalog (RCAT12c). Demo databases environments have been easily managed thanks to DBI DMK tool. oracle@vmreforadg01:/home/oracle/ [RCAT11G] sqh SQL*Plus: Release 11.2.0.4.0 oracle@vmtestoradg1:/home/oracle/ [RCAT12C] sqh SQL*Plus: Release 12.2.0.1.0   Current configuration Displaying the list of databases registered in the RCAT11g catalog. SQL> select instance_name from v$instance; INSTANCE_NAME —————- RCAT11G SQL> select * from rcat.rc_database;     DB_KEY  DBINC_KEY       DBID NAME     RESETLOGS_CHANGE# RESETLOGS ———-…

 
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Clemens Bleile

Running the Oracle Client on a Raspberry Pi

By | Database Administration & Monitoring, Database management, Development & Performance, Oracle | No Comments

What are the possibilities to use a Raspberry Pi computer as an Oracle client? Besides other things I’ll show a possibility in this Blog to run the fat/thick Oracle Client on a Raspberry Pi! REMARK: All examples below were made with an Rasperry Pi 3 and the OS Raspbian, which can be downloaded from https://www.raspberrypi.org/downloads First of all what’s possible with Java and Thin Clients? Running the Java-Programs sqldeveloper or its counterpart in command line…

 
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Nicolas Penot

Automate OVM deployment for a production ready Oracle RAC 12.2 architecture – (part 02)

By | Database Administration & Monitoring, Database management, Hardware & Storage, Operation systems, Oracle | No Comments

In this post we are going to deploy a R.A.C system ready to run production load with near-zero knowledge with R.A.C, Oracle cluster nor Oracle database. We are going to use the “Deploy Cluster Tool” which is provide by Oracle to perform Oracle deployment of many kind of database architectures you may need like Oracle single instance, Oracle Restart or Oracle R.A.C. This tool permits you to choose if you want an Enterprise Edition or…

 
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Michael Hein

Naming of archivelog files with non existing top level archivelog directory

By | Database Administration & Monitoring, Database management, Oracle | No Comments

In Oracle 12.2 an archive log directory is accepted, if top level directory does not exist: oracle@localhost:/u01/app/oracle/product/12.2.0/dbhome_1/dbs/ [DMK] ls -l /u02/oradata/DMK/ total 2267920 drwxr-xr-x. 2 oracle dba        96 Dec  6 05:36 arch … Now database accepts this non existing archivelog destination: SQL> alter system set log_archive_dest_3=’LOCATION=/u02/oradata/DMK/arch/arch2′; System altered. But not this: SQL> alter system set log_archive_dest_4=’LOCATION=/u02/oradata/DMK/arch/arch2/arch4′; alter system set log_archive_dest_4=’LOCATION=/u02/oradata/DMK/arch/arch2/arch4′ * ERROR at line 1: ORA-02097: parameter cannot be modified because specified value is invalid…

 
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