Infrastructure at your Service

All Posts By

Oracle Team

Oracle Team

Unable to add physical standby database

By | Database Administration & Monitoring | No Comments

Recently I tried to setup some new physical standby databases and got the following strange message: DGMGRL> ADD DATABASE “XXXX” as connect identifier is “XXXX” maintained as physical; Error: ORA-16698: LOG_ARCHIVE_DEST_n parameter set for object to be added Often you can read, that you have to check parameter log_archive_dest_2 on primary side. But this error message can also occur if log_archive_dest_2 on standby site points to another standby database. Solution is following command on standby…

Read More
Oracle Team

Second Meetup SOUG / DOAG /AOUG Region Lake of Constance

By | Database Administration & Monitoring | No Comments

Tuesday last week I attended the second meeting of SOUG region lake of constance which took place at Robotron Switzerland in Wil SG. Eleven people attended this event, Georg Russ hold a quite interesting presentation about “Hacked Biometric Data”. He told about how to fake finger prints, iris images, face ids and patterns of hand venes. After this presentation a general discussion about security and other Oracle related themes took place. It was a good…

Read More
Oracle Team

Cause for looping sssd

By | Operation systems | No Comments

In RedHat Enterprise Linux 7, the sssd daemons can connect to active directory servers. Default behaviour is to update DNS entries dynamically. If a statical DNS entry already exists this can lead to a CPU consuming sssd_nss daemon. To prevent this behaviour, the dynamic DNS updates should be switched off with this setting in every doman section of config file /etc/sssd/sssd.conf: dyndns_update = False After that sssd should be restarted to take this change effect.

Read More
Oracle Team

When you change the UNDO_RETENTION parameter, the LOB segment’s retention value is not modified

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

Below, I will try to explain, a particular case for the general error : ORA-01555 snapshot too old error.. Normally, when we have this error, we are trying to adapt the retention parameters or to tune our queries. SQL> show parameter undo; NAME TYPE VALUE ———————————— ———– —————————— temp_undo_enabled boolean FALSE undo_management string AUTO undo_retention integer 3600 –extended from 900, undo_tablespace string UNDOTBS1 But, are some scenarios where the above rule is not working . We…

Read More
Oracle Team

How to extract sql statements with awk

By | Database Administration & Monitoring | No Comments

A common problem is to extract sql statements out of a sql file e.g. produced by full metadata impdp. Often these files are too big to be edited with vi. Following statement extracts all sql statements with “CREATE MATERIALIZED VIEW” at the beginning with awk: cat impdp_full_metadata.sql | awk ‘BEGIN{ FLAG = 0 } { if( $0 ~ /CREATE MATERIALIZED VIEW/ ) FLAG=1; if(FLAG != 0) print $0; if ($0 ~ /;/ ) FLAG=0; }’…

Read More
Oracle Team

How to disable ACLs in Oracle 12c

By | Database Administration & Monitoring | No Comments

A common problem in Oracle 12c is, that ACLs are often not wanted to limit connections from database to other hosts. To disable ACLs is not that easy, so the best way is to enable connections and resolutions to all hosts for all users like following example: BEGIN DBMS_NETWORK_ACL_ADMIN.APPEND_HOST_ACE( host => ‘*’, ace => xs$ace_type(privilege_list => xs$name_list(‘resolve’), principal_name => ‘PUBLIC’, principal_type => xs_acl.ptype_db)); DBMS_NETWORK_ACL_ADMIN.APPEND_HOST_ACE( host => ‘*’, ace => xs$ace_type(privilege_list => xs$name_list(‘connect’), principal_name => ‘PUBLIC’,…

Read More
Oracle Team

Create a primary database using the backup of a standby database on 12cR2

By | Database Administration & Monitoring, Database management, Oracle | One Comment

The scope of this blog will be to show how to create a primary role database based on a backup of a standby database on 12cR2. Step1: We are assuming that an auxiliary instance has been created and started in nomount mode. rman target / restore primary controlfile from ‘backup_location_directory/control_.bkp’; exit; By specifying “restore primary” , will modify the flag into the controlfile, and will mount a primary role instance instead of a standby one….

Read More
Oracle Team

DOAG day “database migration” in Mannheim at 19.02.2019

By | Database Administration & Monitoring | No Comments

Yesterday I attended DOAG conference in Mannheim about migrating Oracle databases. First presentation was about challenges about migrating to multitenant databases. With Oracle 20 it is probably not possible anymore to create a non CDB database or to upgrade from a non CDB database. So in the next years all databases have to be migrated to multitenant architecture. Problems with licensing, different charactersets were covered and some migration methods to PDB were shown. In the…

Read More
Oracle Team

Recover a corrupted datafile in your DataGuard environment 11G/12C.

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

On a DG environment, a datafile needs to be recovered on the STANDBY site, in two situations : when is deleted or corrupted. Below, I will explain  how to recover a corrupted datafile, in order to be able to repair the Standby database, without to be necessary to restore entire database. Initial situation : DGMGRL> connect / Connected to “PROD_SITE2” Connected as SYSDG. DGMGRL> show configuration; Configuration – CONFIG1 Protection Mode: MaxPerformance Members: PROD_SITE2 -…

Read More
Oracle Team

Looping sssd_nss

By | Database Administration & Monitoring | No Comments

Often Linux systems are connected to LDAP via sssd. A high CPU consuming sssd can be seen in top, like below ( e.g. 89.4 % CPU usage): 9020 root 20 0 1296344 466780 333364 R 89.4 0.8 41:20.17 sssd_nss 27227 oracle 20 0 2371676 48320 29732 S 4.3 0.1 27:00.70 oracle One reason could be default configuration of /etc/nsswitch.conf: passwd: db sss files shadow: db sss files group: db sss files This configuration causes sssd_nss…

Read More