Category Archives: Database

ORA-29283: invalid file operation using UTL_FILE.FREMOVE

I’ve been breaking my head over a problem I had with the UTL_FILE.FREMOVE command trying to remove a file created by another (not oracle) process. On *nix command line, logged in as user oracle (same as database) I’m able to … Continue reading

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ORA-19809: limit exceeded for recovery files

In our cloning procedures we use the RMAN “DUPLICATE” command for duplicating databases. This all went fine for a long time until one moment we start getting errors during the duplication process (from the point where media recovery gets started). … Continue reading

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Determine versions of connected Oracle clients

Last week I was trying to find a way to determine the version of the Oracle clients that are connected/connecting to databases from these databases. We cannot connect to each application server to figure out the used version and certainly … Continue reading

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Cryptographic flaws in Oracle Database authentication protocol

Recently a security researcher (Esteban Martinez Fayo) made the world aware of a problem with the O5LOGON Oracle database authentication protocol (used in 11g – 11.1 & 11.2). This problem, known as CVE-2012-3137, makes it relatively simple for attackers to … Continue reading

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Linking Oracle BBED in 11g

Warning: I use the Oracle Block Browser and Edit tool (bbed) for studying the internal structure of database blocks. Be very careful using the tool, you can destroy blocks using this tool so make sure you know what you are … Continue reading

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Oracle Database – 11.1.0.7 in extended support

As of 1 September 2012 Oracle database release 11.1 (terminal release 11.1.0.7) will be in Extended Support. Here is list of some database releases with start dates for extended support and sustaining support: Release Extended Support Start Sustaining Support Start … Continue reading

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Where does SQL*Plus look for configuation files on Solaris

This post will show you the order in which SQL*Plus for Solaris reads the configuration files like the tnsnames.ora. tnsnames.ora $HOME/.tnsnames.ora $TNS_ADMIN/tnsnames.ora /var/opt/oracle/tnsnames.ora $ORACLE_HOME/network/admin/tnsnames.ora If the specified alias is not found in (or the file does not exists) in $HOME/.tnsnames.ora … Continue reading

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sqlnet.expire_time – to restart or not to restart

We had a situation where we had to set the sqlnet.expire_time parameter in the sqlnet.ora file to avoid firewall dropping “inactive” sessions. The only problem was that we were not allowed to restart the listener or the database instance. Searching … Continue reading

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Creating database links for another schema

There are situations (like after cloning databases) where you, as a DBA, want to create database links in other schema’s, for which you don’t have the password. Unfortunately the security of Oracle doesn’t allow (even SYS) you to drop/create database … Continue reading

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Password History – Reusing a password

By setting either one or both the profile limits PASSWORD_REUSE_MAX or PASSWORD_REUSE_TIME are set to anything other than UNLIMITED, Oracle somewhere keeps a history of passwords used by a user. This password history is stored in a table with the … Continue reading

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