Use USE_DB_RECOVERY_FILE_DEST for self-managing deletion rules of the Archived Log files

When using the Fast Recovery Area for storing archive logs, one probably wants to use this location to make use of the self-managing deletion rules of files.

One of these rules is that files are obsolete under the retention policy are eligible for deletion. When for instance RMAN needs space for backup (without delete obsolete option), Oracle will do a similar ‘delete obsolete’ command to make space in the Fast Recovery Area.

For archived logs to be eligible, one MUST use the USE_DB_RECOVERY_FILE_DEST setting for log_archive_dest_x. If the actual location is used, Oracle does not include archived logs in the self-managing deletion rules of files!!! Continue reading

Public yum package ‘oracle-validated’ problems on 64bit OEL

I was preparing some fresh installed OEL5.5 machines for database software installation, but after running ‘yum install oracle-validated‘, the OUI did not pass the prerequisites on two packages. It seems it did not install unixODBC-devel x86_64 and libaio-devel x86_64.

Their Linux may be unbreakable, but their ‘oracle-validated’ package on the public yum server seemed to be broken. Continue reading

Theoretical problem when WebLogic’s NodeManager is using a start script

Many people will use the WebLogic’s NodeManager to use the start script for starting Managed Servers:

StartScriptEnabled=true

The NodeManager will start the Managed Server using the script and monitor the Managed Server when it fails.

One of the mistakes people can make is creating their own start script and start the Managed Server using ‘nohup &’ within this script: Metalink [ID 984122.1] and [ID 861098.1]. The script will finish and the server keeps running, but the NodeManager thinks the Managed Server has failed… Continue reading

Oracle Database version compatibility and support matrix

— Checked for relevance on Januari 21, 2017

The Oracle Database version compatibility matrix and version support status matrix are almost mandatory when installing or upgrading clients or servers.

For information about patches, go here: Oracle database patches for Linux and Windows (on Metalink).

For announcements of security fixes, go to Critical Patch Updates, Security Alerts and Third Party Bulletin.

Oracle Database client / server version compatibility matrix

Oracle calls this Client / Server Interoperability Support, Note ID 207303.1

Oracle Database version release support status matrix

Oracle calls this the Database Releases Support Status Summary, Note ID 161818.1

You will be redirected to Oracle Support and you must be registered to gain access to the pages. I did not include the matrices, because these change over time.

Oracle Information about Windows 32 / 64 bit database and client versions

Certification Information for Oracle Database on Microsoft Windows x64 (64-bit), Doc ID 1307195.1

Oracle 11g AMM: MEMORY_TARGET, MEMORY_MAX_TARGET and /dev/shm

I knew in Oracle 11g with Automatic Memory Management (AMM), the database was able to give unused memory back to the OS, controlled by MEMORY_TARGET and MEMORY_MAX_TARGET.

This mechanism is present in 11g since day 1 (in 2007), but I never actually played with it.

MEMORY_TARGET and MEMORY_MAX_TARGET

The Oracle documents state the following:

MEMORY_TARGET specifies the Oracle system-wide usable memory.
MEMORY_MAX_TARGET (…) decide on a maximum amount of memory that you would want to allocate to the database for the foreseeable future.

So my guess is, MEMORY_MAX_TARGET (static) is the maximum you can set MEMORY_TARGET (dynamic) to. A couple of days ago, I wanted to experiment a bit with these memory settings.

Continue reading

Using a Putty private key in Android ConnectBot

I have been trying to import a private key into ConnectBot for Android.
The key I’m using is working fine when using Putty, but does not work for ConnectBot.

To make it work for ConnectBot, you need to have a OpenSSH version of this file.
Luckily one can also use PuTTYgen to create an OpenSSH key.

Puttygen

In Puttygen, do the following:

  1. Load the private key: [File] -> [Load Private Key] (*.ppk)
  2. Enter passphrase if applicable
  3. Goto: [Conversions] -> [Export OpenSSH key] and save

Continue reading

Oracle Database Undo space explained

In this blog post I will talk about the basic workings of Automatic Undo Management, which can cause ORA-01555 and ORA-30036 issues.

The scope is Automatic Undo Management used in 10g and 11g, but has to be explicitly set for 9i (UNDO_MANAGEMENT = AUTO). Manual Undo Management is out of scope for this blog.

The Undo tablespace is a normal tablespace like any other, but only Oracle is controlling what is happening inside it.

Undo something

The Undo tablespace is used for several features: ROLLBACK, READ CONSISTENCY and FLASHBACK technology. Continue reading